OPEN-TOP STORMER; Meet the maddest Mercedes of all.(News)

Byline: GREG KABLE

Sometimes it's best not to ask why, and simply be grateful a car exists at all. That's the way it is with the CLK DTM cabriolet, arguably the most outlandish Mercedes-Benz road car ever put into production. Attempting to make sense of this 5.4-liter, 582-hp supercharged V8-powered monster is a pointless exercise-the car makes no rational sense. But with a 4.0-second 0-to-62-mph time and a top speed limited to 186 mph, who needs rational?

Billed as the world's fastest four-seat open-top, this breathtakingly expensive car is proof Mercedes will occasionally shrug off its corporate straitjacket and follow its instincts. The DTM cabriolet is a car that not only breaks with convention, but abandons it.

Inspired by Mercedes' 2003 DTM winner, the aggressively styled car is the second act in the firm's efforts to add vital performance to its lineup. The first, the mechanically identical CLK DTM coupe, sold out faster than Mercedes anticipated, at $225,000.

Chances are you'll never see a CLK DTM cabriolet on the road. Like its sibling, AMG will produce just 100 for sale worldwide, at $336,000 apiece; already it is sold out.

The cabriolet looks like the race car and is adorned with the same body kit. Some of the kit isn't functional: Those wild wheel-arch flares have plastic stoppers. But the functional parts include the big front air dam and the towering rear wing that, like the doors and gas filler flap, are made of carbon fiber.

Step inside and you're confronted by expensive-looking one-piece carbon fiber door trim and dashboard trim applications. The front and rear seats are supported by carbon fiber shells as well. You sit low in front of a thick-rimmed steering wheel complete with airbag, scroll buttons for the trip computer and two large shift paddles for the gearbox.