The AMG version of Mercedes' newest C-Class sedan debuted at the Los Angeles Auto Show and will be available for general consumption around tax time, but the convertible CLK63 AMG is already at dealers. It is the first C/CLK-Class with more than 400 horsepower, about a 120-horse bump from the previous CLK AMG, and, excepting the CLK63 Black series — essentially a $135,000 street-legal version of a German Touring class race car — is the first to near a six-digit sticker.

If you find the less-than-economical idea of putting a 6.2-liter V-8 in a small four-seater unappealing, you can stop reading here and go complain to a Corvette buyer with the same size engine, less power and just two seats. Or just go for the CLK350 or 550 cabrios with V-6 or V-8 power; either will push double any U.S. speed limit but they haven't quite the same atmosphere as the 63.

Contrary to popular belief the engine in the CLK63 has no Mercedes parts — it was developed from the ground up and is built at AMG — and it isn't 6.3 liters. In fact it's almost exactly 6.2 liters but Mercedes considers the 6.3 tag from 35 years ago to have some benefit; Chrysler does the same thing with their "new" Hemi engine, and the 6.2 is every bit as sensational as the 6.3 was.

The CLK is the smallest Benz to get the 6.2 and even detuned to 475 hp in the CLK it has plenty of punch to overwhelm the rear tires and reach 60 mph in less than five seconds or ruin your coif in less than ten; similarly heavy CLK Black Series coupes get 500 hp and other tweaks as part of the $45,000 price premium and C sedans get 451 horses. All of them use seven-speed AMG "Speedshift" automatics because unlike their German competitors Mercedes-Benz USA has an allegiance to torque converters and does not ship us an AMG model with a clutch; it's very good as automatics go, better than some sequential manual gearboxes and most likely faster than you.

Ludicrous power requires control, which the CLK delivers with very cross-drilled and vented big brakes, the front endowed with six-piston calipers and composite hat-and-rotor design; the end result of pressing the brake pedal hard is much like a stuntman's drop a sudden stop with no pain or damage. The suspension is predictably balanced and grip from the low-profile 18-inch P-Zeroes is commendable up until you tickle the gas pedal and force the rear end to cope with lateral forces and that huge powerplant; never fear, stability control won't let you slide out. As the sports model the ride is firm and only somewhat forgiving; daily driving isn't a chore but you do want to make an effort to avoid recessed manhole covers, speed bumps, and roads due for maintenance.

The fat-rimmed steering wheel requires deliberate action and rewards it accurately; there's no super-slick wheel spinning for parking here. Both pedals have lots of travel, a plus for getting into that horsepower well smoothly and minimizing bug-on-the-window faces from too much brake too fast, so there is no quick brush of the brakes for shaving off speed without moving the pedal noticeably.

Lowering the top is a one-button operation and it does take away some trunk room, leaving enough to still legitimately call it a trunk. It's a solid structure, as you'd expect from a two-ton Benz, and only those surfaces previously referenced will blur the inside mirror. On cars with lighter-color paint and the top up, however, the painted rear deck inside the rear window makes the glass appear dirty or foggy and may disturb your view to the rear. Wind-blockers are supplied for two-up driving, but really, if you just want sun and no breeze, get a sunroof — you'll miss much of the engine's sensuous whirring windup and baritone bellow if you keep closed.

Although the 63 has a deeper grille, side skirts, small trunk spoiler and dual exhaust outlets it doesn't appear as menacing as many sports models, which frequently proves beneficial. AMG is proud of their product, so much so that we quit counting logos at 16 and hadn't even opened the hood or trunk yet. The hood slopes more than you think from outside so the front corners aren't seen and you'll have no trouble with vision on night drives behind the (optional) bi-Xenon active headlamps and front and rear fog lamps.

Although you expect thick windshield pillars in convertibles the CLK is so well engineered in this respect the pillars are narrower and outward vision better than in any of those slot-window sedans and Hummers.

The leather is supple and the trim Alcantara, aluminum and the odd bit of occasional hard plastic, but it's all business inside. Instruments are dominated by a central, 200-mph speedometer housing a digital display within that will change colors if it needs to get your attention; to the right is the tachometer and to the left an equally large analog clock because the Germans have a thing about schedules. Down the center are the navigation screen with single-play CD and nav-DVD slots behind (CD changer in the glovebox), ancillary controls like seat heaters and ESP, and dual-zone climate control. The interface system, known in Benz-speak as COMAND, is getting better and the CLK does without a central control knob.

Sport seats with long cushions in perforated leather do an excellent job of maintaining a good driving position regardless of road or hours behind the wheel; both front seats offer three-setting memory and optional cooling, while the driver's gets four pneumatic adjustments for lumbar and backrest width to secure your ribcage. Rear seats are cozy and more useful than those in a Jag XK, Porsche 911, even a bit better than BMW's "big" M6; the riders there have AC vents, full roll-down windows with their own controls, pleated leather side panels with airbags, pop-up headrests/rollbars, and a center armrest the front passenger will envy. Between the rear buckets is a pair of subwoofer ports for the harman/kardon sound system with Sirius satellite radio that manages to deliver good tunes top up or down.

The CLK63 AMG is one of those do-everything cars for people who have lots of cash but little parking or garage space; it delivers everything you'd expect from the AMG tag. Alas, we couldn't help wonder sometimes if we should try playing an addled celebrity attempting to drive into paparazzi with it.

(Whale, a longtime Ventura County resident, has been breaking parts for 29 years, and writing about it for 21.)

2008 Mercedes-Benz CLK63 AMG cabrio

Engine: 6.2-liter DOHC V-6, 475 bhp

Length/width/height (in.): 182.3/68.5/55.4

Weight: 3,948 lbs.

MPG city/hwy/observed: 12/18/18.3

Base warranty: 4 yrs/50,000 miles

Price as tested: $98,245

Alternatives: Audi RS4, BMW M6