Mercedes will be unwrapping a four-door cabriolet based on the long-wheelbase S600 at the 2007 Detroit Auto Show. It's called Ocean Drive, probably because that's where it belongs--Ocean Drive in Miami Beach, Laguna Niguel or Cape Cod. It wants to be that kind of car: overtly ostentatious, a millionaire's toy, about as understated as a rap star in a pink mink coat. There is no doubt about it: this Benz could have easily been born with a Maybach badge. After all, it would compete in the same mega-money league as the upcoming Rolls-Royce convertible or the Bentley Azure.

Unlike all other luxury droptops this side of a 1964 Lincoln Continental convertible, the Ocean Drive's sumptuous cabin is accessible via four doors. Proximity sensors activate the concealed handles, so it's almost a relief that they still let you do the opening and closing with your own hands. Thanks to the generous 124.5-inch wheelbase, this is a proper four-seater with enough room to swing pedigree cats front and rear.

At 208 inches in length, confined parking spaces are definitely off limits for this two-tone Ocean Drive, which combines a champagne pearl upper with an alu-beam champagne lower. Looks quite cool, really, and matches well with the bronze tinted windows. The roof is lined with a fabric made of two-tone yarn, so it appears matte from one angle and shiny from another. According to Mercedes, it "mimics the chameleon character of the metal flake paint while its luster is reminiscent of luxury wood."

Spanning a record acreage of more than 34 square feet, the canvas top forms an arc that is 87 inches long when fully extended. The electric motors and valves that open and close this massive awning ensure that the process is executed in perfect synchronicity and in only 20 seconds. Padded by a thick layer of cotton wool and lined with bright cloth, the roof disappears completely under the double-hinged SLK-style tonneau cover. When closed, a heavy chrome brace covers the seam between canvas and metal. When open, the exposed bird's-eye maple parcel shelf looks a bit like the quarter-deck of a high-end motor yacht.

Flanked by tucked in front wings, the tall and pointed bow of the Ocean Drive is also more boat than car. Designed to part the waves with maximum attention, the trademark grille is 30 percent bigger than that of an S-class. The other characteristic feature of the Merc's front end are space-age LED headlights each consisting of 35 LEDs. At night, they form two inverted Cs, incorporating daytime running lights as well as turn signals. The same visual theme is repeated in the back where the LED tail- and brake lights are separated by slim horizontal chrome crossbars.

Combining styling cues from the S-class and the CL with a new, statelier overall shape, the Ocean Drive wants to be a highly visible status symbol that relays the classic brand values of solidity, quality, comfort, value and safety. At the same time, the designers tried to send emotional messages like passion, fascination and innovation. In sync with so many current Benzes, this concept car is not only about architecture but also about ornamentation and decoration.

Point in case are the ritzy 36-spoke high-gloss aluminum wheels shod with 275/35ZR21 tires. Says Peter Pfeiffer, senior vice president design: "This vehicle epitomizes the profile and the philosophy of Mercedes-Benz. It blends familiar styling themes with fresh a visual approach, it merges strong surfaces to create a trademark geometric whole, and it uses no more than a few well defined lines to express elegance and power." At a glance, the XXL drop-top looks almost bland and quite static. But the proportions do grow on you, and while the stance is definitely cosmopolitan with an American touch, the detailing radiates the typical Teutonic thoroughness.

Inside, there is more bird's-eye timber which can't make up its mind whether it wants to look grey or beige. Maple is also the material of choice for the door panels, the dashboard upper, the centre console and the armrests. While the A-pillars and the instrument panel are covered with brown leather, the lower part of the cabin and the inner seat segments are trimmed in ivory cloth. The same color hide is used on the door panels, the seat backs and the outer cushions - tasteful but likely impossible to keep clean. Special features include a bespoke wood-and-chrome steering wheel, an in-dash chronometer, a rear seat DVD system and the inevitable champagne cooler, which holds one bottle and two glasses. Beneath the carbon-clad body structure, we find the S600's drivetrain - a 510-hp twin-turbo V-12 mated to a five-speed slushmatic. To celebrate the occasion, the engine bay has been given the full motor show treatment.

Will the Ocean Drive ever make it to a showroom near you? We don't think so. It may evolve into a Maybach providing that brand really does have a future. But if Daimler-Chrysler ever signs off a non-homeopathic four-door convertible, it will most probably be pitched by Chrysler as a derivative of the next 300C. Mercedes-Benz is much more likely to launch a two-door CL cabriolet. Available with 4Matic as a new option, that luxury soft-top is expected to appear late in calendar year 2008.