Pounding the point home is the CL's hardtop design: As with all of its predecessors since 1958, there is no central B-pillar aft of the doors to break the sleek lines of the body.With the windows down, the look is sexy and the view out is panoramic, recalling cars of the Fifties and Sixties when hardtops were in vogue.

Where the current CL breaks most from tradition is in its sheer excess.Pricey and pretty as they were, the big Mercedes coupes of the Fifties, Sixties, and even Seventies were compact compared to contemporary U.S.cars, and were powered by relatively small-displacement engines.The current line qualifies as truly massive, in size, weight, and horsepower.

The most significant change for 2009 is that the CL550 now has the Mercedes-Benz all-wheel-drive system, 4MATIC, as standard equipment.It is thus called the CL550 4MATIC.

The CL550 4MATIC has a powerful 382-horsepower 5.5-liter V8.The CL600 packs an insanely powerful 510-hp twin turbocharged 5.5-liter V12.There are also two AMG versions: The ridiculously powerful CL63 AMG with its 518-horspower 6.2-liter V8, and the preposterously powerful CL65 AMG with its 604-horsepower 6.0-liter twin-turbo V12.We're running out of adjectives to describe the performance of these engines.

Like its predecessors, the current CL manages to be sporty without being a true sports car.Securing the right exterior proportions meant making the CL significantly shorter than the S-Class, upon which it is based.This results in a close-coupled, intimate interior, the kind historically associated with coupes from time immemorial.We'd call the rear passenger area cramped, though similar models from BMW and Bentley actually have even less rear legroom.The CL is for being seen in.If you want practicality in a big Mercedes, buy an S-Class sedan.

In the front seats, the CL is a car that is as wonderful to be in as to be seen in.Its interior is sumptuous and inviting, dressed in the finest materials and tailored to perfection.Burled walnut, supple leather, brushed aluminum and designer-quality knobs and switches are everywhere you look and touch.The standard equipment list bulges with luxury items no one actually needs but almost anyone would love to have, from a harman/kardon 600-watt, 11-speaker audio system to soft ambient mood lighting.Through the Mercedes COMAND central computer interface, many dozens of settings for seats, climate, sound, lighting, GPS and much more can be customized to your personal preferences.

The CL offers a breathtaking array of safety technology as standard equipment: Nine airbags, dynamic stability control, traction control, anti-lock brakes, automatic brake drying, seatbelt pre-tensioners, and automatic window closers, to name a few items.

In short, the CL is ultra-luxurious, sexy, technologically advanced and very stylish with excellent all-around driving capabilities.With its occasional rear seating for two, it's roomier than a sports car but tighter than a sedan.We think the CL will be extremely appealing to a relative few drivers who fall in love with it and can afford the luxury of choosing stylish lines over day-to-day practicality.

Standard CL equipment is comprehensive.The seats, doors and instrument panel are all leather covered, and burled walnut wood trim is used liberally.The front seats are 14-way adjustable and heated, and have a three-setting memory capability that also sets the electrically telescoping-and-tilting steering wheel and side mirrors.

The standard audio system is a harman/kardon Logic7 5.1 Digital unit with 11 speakers and a six-CD in-dash changer (with memory card slot).Sirius satellite radio is standard.There's a power sunroof overhead and a power rear-window sunblind in the rear parcel shelf.Doors have power assist closing mechanisms, and the trunk is electrically powered.

The Mercedes COMAND system, a centralized computer interface with a dash-mounted flat panel screen, is also standard.It enables access to many of the car's accessories including GPS navigation, phone, climate controls, and other customizable features (exterior courtesy lights, seat settings and voice command setup).Bi-Xenon headlights are standard, too, as is Parktronic, a distance sensing parking aid.All CLs are equipped with ABC active suspension, which utilizes electro-hydraulic cylinders to control body roll and some damping functions.

The optional Premium 2 Package ($3370) for the CL550 4MATIC includes heated and ventilated front seats, a keyless entry system, multi-adjustable front seats fitted with pneumatic chambers that adjust cushion firmness and lumbar support, a night vision system with an in-dash screen, and a rear backup camera.A heated steering wheel ($470) is also available.A Sport Package ($5690) adds special aerodynamic pieces and larger, 19-inch wheels (18-inch wheels are standard).Or choose 19-inch wheels by themselves ($1230).

The CL63 AMG has the heated steering wheel, and the body kit, and includes 20-inch wheels as standard; Premium 2 equipment is optional ($2120).Optional for both V8 models are Distronic Plus distance monitoring cruise control with Parking Guidance and Blind Spot Assist ($2880), and an iPod integration kit ($425).Buyers seeking even more exclusivity can choose among two designo edition combinations of exterior color and interior leather and trim (Espresso or Graphite).

Most of the above are standard on the CL600.The only options it offers are the iPod kit, the two optional wheel choices, and the designo editions.Ditto the CL65 AMG, except that it, like the CL63 AMG, already comes with 20-inch wheels.

Safety features on all CLs include a pair of two-stage front airbags, a driver's-side knee airbag, two front side airbags, two rear side airbags, and side head-curtain airbags for front and rear passengers.There are seatbelt pre-tensioners for the front passengers' belts.Windows close automatically in a crash, and a sunroof closing feature activates in rollovers.Also standard: ABS with electronic brake-force distribution and automatic wet-weather drying, dynamic stability control, traction control, and Distronic cruise control.Optional safety equipment includes Distronic Plus distance-sensing cruise control with Parking Guidance and Blind Spot Assist.

From nose to tail, the CL is something out of the ordinary.Seen from the front, it's instantly identifiable as a Mercedes-Benz from its three-slat grille, long a staple of Benz sport models and SUVs.The famous three pointed star emblem is front and center and as large as a dinner plate, just to be sure you don't mistake the CL for any other brand.As if you could.

At 199.4 inches long, this is a large car, and its size gives it presence.

The front end stretches wide and sweeps back into a pair of prominent flared front wheel openings, a design element derived from the S-Class sedans with which the CL shares its underpinnings.Its 73.7-inch width makes it look solidly planted and substantial.There's surprisingly little chrome up front and we think it could use a bit more twinkle to announce its arrival.But it's still a knockout first impression.Projector beam headlights add the final bit of modernity to the nose.

It's the sweep of the roof that makes the CL's compelling style statement.The top arcs dramatically over the side glass and down into the C-pillar without the interruption of a B-pillar, the central support post most cars have between front and rear side windows.The roofline is sleek.And this is a true hardtop; you can drop the large side windows down for a panoramic view and an open-air feeling.Handsomely wrought chrome trim framing the large side-window opening emphasizes both its shape and the absence of the second pillar.In profile, the CL is gorgeous and sporty.

Even as it drives away, the CL keeps your attention.The rear window's horseshoe-like shape is especially intriguing, and not seen anywhere else in the automotive kingdom.Below the backlight (rear windscreen) the tail tapers gracefully into a pair of large taillights and a taut trunk lid wearing a subtle built-in rear spoiler at its top edge.Sedans don't look like this, and that's just the point.

Outside of the model nomenclature on the deck lid, the CL550 4MATIC and CL600 models are essentially identical from the outside.

The AMG models can be identified by distinctive grilles, wherein the Mercedes star is supported by four chrome bars over black mesh, and by their more muscular-looking front bumper with large air intakes housing round, chrome-ringed fog lights.Contoured side skirts carry the aggressive lines of the front bumper to the rear, where four oval exhaust outlets punctuate the black air diffuser set into the unique rear apron.Front fender badges read 6.3 AMG on the CL63 AMG and V12 Biturbo on the CL65 AMG.Both roll on 20-inch, five-spoke alloy wheels, but with a slimmer-looking twin-spoke design on the CL65 AMG.

Ensconced in the driver's seat, you immediately register the raked-back windshield and low roofline pressing down from above, creating a narrow viewing port ahead.The CL is just 2.2 inches lower than an S-Class sedan, but it feels much lower than that.

The surroundings are a sybarite's delight.There's almost nowhere your hand falls that you're not touching either glove-soft leather, burled walnut, brushed aluminum or chrome.The instrument panel cover is stitched in leather, as are the door panels and seats, buckets front and rear.The steering wheel is wood with leather grips at the nine and three o'clock positions.It houses buttons in front for the phone and COMAND system, and switches behind the top spokes for manually shifting the seven-speed automatic transmission.

The exterior's curvilinear theme is repeated in the interior.The center console curves gently into the center stack, and the interior front door panels arc outward subtly at the elbow area, the shape accented by delicate chrome accent strips.The door armrests are an artful combination of burled walnut stacked with leather covered padding.At night, soft ambient light glows from tiny hidden light strips in the doors' upper sections and across the middle of the dash.The only plastic pieces of note are the speaker covers in the lower front corner of the doors, where you hardly notice them.

The walnut trimmed center stack contains a thin row of easy-to-operate brushed aluminum climate control switches, a hidden compartment for the CD changer and a pair of vents flanking a square analog clock that looks like it could double as Patek Phillipe wristwatch.

Living in this car is every bit as satisfying as looking at it.The center console is home to a push-and-turn mouse-type knob that is the main interface to the COMAND system and its thin-film transistor (TFT) display.The screen is housed in a hooded binnacle to the right of the driver's gauges, which also are TFT technology.

For cars equipped with the optional night vision system, the large speedometer in front of the driver transitions to a second viewing screen whenever the system is activated.Several other buttons arrayed around the mouse control the suspension's sport and comfort modes (linked to the transmission shift program), the sound system and the multi-function seats' firmness and adjustment.

Between the steering wheel buttons and mouse, you're afforded several paths of access to the multiple layers of the CL's navigation, seating, climate control and sound systems.You can set your preferences for everything from radio stations to auxiliary lighting.You can program the voice control to recognize your particular intonations.You can input GPS travel information and requests.And you can access, activate or cancel dozens of other systems, including radar distance sensing, daytime running lamps, tire pressure monitoring, and much, much more.

At times we wished it were easier to access some of the systems through COMAND; it took several steps where one touch of a conventional button would have worked more directly.But owners of similar systems in Mercedes-Benz and other luxury cars say that after an initial acclimation period, using the system becomes less cumbersome.And realistically, for a vehicle with this many features a centralized computer interface is the only way to accommodate them.

At least you'll never want for aural entertainment.The harman/kardon system's performance through its 11 speakers is purely angelic.And the GPS works about as well as any we've encountered, with an easy-to-read rolling map and good graphics.

The CL's front seat comfort is beyond reproach.The front cabin offers all the legroom, width and headroom anyone but an NBA forward could need.The power front seats are wonderful; the width and pocketing of the cushions provide just the right amount of support to the back and under the thighs, and, with the full range of adjustments available, almost anyone can get comfortable.Even the length of the front-seat lower cushions is adjustable for just the right amount of under-leg support.Our car was equipped with the optional active ventilated seats, which contain several small fans to circulate cool or warmed air through the perforated leather seat covering.Pneumatic bladders built into the seats can be programmed to adjust the firmness of upper and lower side bolsters, back rest, and shoulder area, as well as lumbar support firmness and location.The seats also offer a massage feature, and it's quite nice, actually.We preferred the fast and vigorous setting; imagine a soft rolling pin making its way from your lumbar region to upper back.The programming is controlled through the COMAND interface using clearly marked pictograms.

The seats can be programmed to automatically inflate upper and lower bolsters when the car turns a corner to provide the driver and passenger with extra lateral support.In that mode we found them abrupt, at times taking us by surprise, and too aggressive.We left that feature de-activated, and opted for more massage.

The AMG models feature a unique sport steering wheel with distinctive aluminum shift paddles, and multi-contour leather sport seats finished with special piping.Completing the AMG interior package is an exclusive analog clock based on the design of the IWC-Ingenieur series.

We found using the COMAND system while underway distracting, but we didn't have much practice.It is complicated enough that it will take an owner a period of time to absorb the combination of button-pushing and knob-twirling-and-tapping that best accesses and adjusts the CL's many features.Exploring the system while on the road divides the driver's concentration.In our week-long test session, we found it best to slow down, pull over into the right lane and stay out of the way while fiddling with the system.We figure at least a month would be required for an owner to fully master COMAND, maybe more.

The CL interior's only real negative is rear seat room.There isn't much.Though the rear buckets are as handsome and almost as comfortable as the front (they lack any adjustability), this is a not a place to spend much time.Despite its full-size 116.3-inch wheelbase (albeit 8.2 inches less than that of the commodious S-Class sedan), the CL's dramatic dimensions mean rear legroom in the small-car range.Plant a six-foot driver behind the wheel and a six-foot rear-seat passenger's knees are jammed against the front seatbacks.Kids and anyone less than 5-feet, 6-inches will fit well enough.And most people will be able to handle the tight rear quarters for local trips to the mall.But this is not the car to take on a cross-country jaunt with four average-sized adults.

Oddly, that lack of interior room may be one of the CL's strongest luxury statements: It's a large car that can afford to ignore the everyday requirement of passenger-carrying practicality.Need more space? Take another car.This is apparently okay in this class: The Bentley Continental GT and BMW 6 Series have even less rear legroom.

Cargo room is just the opposite.The trunk is deep, commodious and finished in a handsome gray carpet.Under the trunk floor is a shallow but still useful cargo tray, and under that a full-sized spare.Liftover height is about average, and the electric powered opening-and-closing feature is always appreciated.

You start the CL with a touch of a big aluminum button to the right of the steering column.We still wonder why being able to keep the key in your pocket makes this a better solution.Then drop it into gear with a column-mounted electronic shift lever similar to the kind BMW is now using.Purists may feel it's an odd and un-sporty throwback to have a shifter moved off of the center console and on to the steering column, but it works well and frees up space.

The 5.5-liter all-aluminum 32-valve V8 is velvety smooth and nearly silent, until you prod it.With 382 hp on tap it rushes the car to speed with a muted, purposeful growl.The seven-speed automatic gearbox shifts imperceptibly in town, smoothly at full throttle and never gets caught in the wrong gear in traffic.Quiet, smooth, sophisticated: This is the way the powertrain in a high-end luxury automobile should behave.

Having a gasoline-fired engine this powerful pulling a vehicle this heavy does create a gas mileage penalty, or two actually.The first is real-world fuel economy: The EPA mileage rating is 14/21 mpg, City/Highway.And that figure triggers the federal Gas Guzzler Tax at purchase, $1300 in this case.

If there's one word that describes the CL road experience, it's silken.On smooth surfaces it feels as if it's riding on glass.Some vibration or road harshness must be penetrating the hushed cabin, but it just doesn't feel like it.The sportier BMW 6 Series coupes register bumps harder and reveal surface imperfections far more acutely.In the Benz, the smaller road irregularities get glossed over.Over larger bumps the ride is less supple than you might expect, almost firm, but not enough to inspire the driver to attack the curves.

The steering has a ball-of-silk feel, less sharp than in the BMW and more relaxed in its responses.Though the steering effort rises with road speed, the feeling remains comfortable, smooth and luxuriously isolated rather than sports-car sharp.This is a car that works its way down a winding road with grace and stability, and the active suspension keeps it cornering quite flat.But the CL doesn't communicate the sense of the road in the way that great sports sedans do.It never gives you the urge to get aggressive, as a BMW 3 Series would.

On the highway, the CL's German DNA is fully in evidence.It has a commanding, solid feel and is dead stable even at extra-legal speed.It's in these upper speed ranges that you notice that wind noise has hardly increased at all.This is autobahn breeding at work.

Using the optional Distronic Plus distance sensing cruise control is an eerie and fascinating experience.The radar-based distance monitoring system automatically slows the CL, using the brakes if necessary, as you close the gap on the car in front.That distance can be set between a hundred and several hundred feet.When the system detects the lane ahead is clear again, it accelerates back to your pre-set speed.All the driver needs do is steer, an odd sensation to say the least.The system works beautifully in light Interstate traffic and reasonably well in moderately denser intra-urban highway environments, though it sometimes annoyed us by slowing sooner for a car up ahead than an average driver would in most circumstances.

There's more to Distronic Plus than active cruise control.The system is tied into a comprehensive in-car safety network.It will sound an alarm if the driver is gaining too fast on the car ahead, meanwhile priming the Brake Assist Plus system to apply full emergency braking as soon as the driver presses on the brake pedal, no matter how lightly it's applied.If the driver doesn't respond to the distance alarm, the system will apply up to 40 percent of total braking capacity automatically to slow the car down.

The Distronic Plus system includes Blind Spot Assistance, with additional sensors in the rear bumper that detect other vehicles approaching in those hard-to-see, over-the-shoulder-and-behind zones to either side.If you signal a lane change or begin to steer from your lane, an arrow lights up in the appropriate side mirror, green for all-clear, yellow for caution.

The Dynamic Rearview Monitor has an enhanced function that scans the size of a parallel parking space and determines if the CL will fit.As before, shifting into reverse activates the camera, and grid lines appear on the speedometer to help guide you into the parking space.

The infrared night vision systems actively projects infrared light from the headlamps.An infra-red camera discreetly mounted in the windshield receives the reflected images and displays them in a high-resolution display in the instrument cluster.The result is akin to a highly detailed black-and-white video image.

Meanwhile, if a frontal crash is imminent, the Pre-Safe Brake system takes action: It tightens the front seat belts milliseconds before impact, moves the front passenger seat to its safest position, closes the side windows to add support for the side-curtain airbags (and to keep occupants' arms inside the vehicle), initiates partial braking to slow the vehicle and will even close the sunroof in a rollover.

We found that, in normal driving, the CL's brakes were confident, effortless and luxuriously insulated.The brake pedal action is progressive and direct.You won't find a smoother set of brakes anywhere.In hard braking the system feels powerful and was free of any fade.Decelerations from even high speed were calm, quiet and drama-free, with not a bit of vibration or noise transferred through the brake pedal or into the cabin.Again, thank the requirements of German autobahn driving.

The CL600 comes with a twin-turbocharged V12 that delivers vastly increased power and even greater smoothness than the CL550.The CL600 produces 510 horsepower and 612 pound-feet of torque, an astounding 56 percent increase over the CL550.The V12 is so smooth and quiet in stop-and-go traffic it almost feels like the car is powered by an electric motor.Yet awe-inspiring acceleration is just a push of the pedal away: Mercedes quotes a 0-60 time of 4.5 seconds for the CL600, smack in the middle of the range for Corvettes, Porsches, and Ferraris.There's so much low-end power on tap that the tires would spin wildly if not for the traction and stability control systems working overtime.Highway acceleration feels like a DVD on fast-forward.We don't know why anyone would actually need this much power in a CL, but it is amazing to experience it.Nearly all of what we reported on the CL550 and its multitudinous systems is true of the CL600, which includes virtually all of them as standard.

The CL63 comes with a 6.3-liter V8 that produces 518 horsepower at 6800 rpm and 465 pound-feet of torque at 5200.This is not simply a larger version of the CL550 engine, but a unique unit sharing no parts with any other Mercedes-Benz V8.Like the CL550 engine, it features four valves per cylinder, variable valve timing, and a variable intake manifold; but its higher-rpm valve system relies on bucket tappets rather than the finger type.Mercedes says to expect 0-60 times of 4.5 seconds.The CL63 is sportier and louder than the CL65.

The CL65 is powered by a 6.0-liter twin-turbocharged and intercooled V12 that produces 604 horsepower and 738 pound-feet of torque, for a claimed rocket ride from 0-60 mph in just 4.2 seconds.Both of the AMG models are electronically limited to 155 mph, compared to 130 for the CL550 4MATIC and CL600.

The AMG models use the same active suspension as the other CLs, but it's tuned for flatter cornering and tighter control of body motion, and stability and traction-control functions are upgraded for the additional power.A button on the center console allows the driver to choose among three different shift programs, Sport, Comfort, or Manual, that fine-tune accelerator pedal response and spring and shock absorber settings.

The AMG models also feature large composite brake discs (15.4-inch diameter in front, 14.4-inch in the rear), to slow them in a hurry, converting all that speed to heat in mere moments.The front discs are not only vented by cross-drilled.Twin sliding calipers on the front brakes combine the performance of a large fixed caliper with the reduced heat transfer of a floating caliper.Providing room for those big binders are 20-inch alloy wheels, 8.5 inches wide in front and 9.5 inches at the rear, wearing low-profile 255/35 front and 275/35 rear tires.Mercedes claims the CL65 can stop from 60 mph in just 116 feet.

Rich Ceppos filed this report to NewCarTestDrive.com from Ann Arbor, Michigan.John F.Katz reported on the AMG models from Harrisburg, Pennsylvania.