09/21/09 2011 Mercedes-Benz Ocean Drive It's tough making a profit in the car business these days, and even top-of-the-market outfits like Mercedes-Benz don't have money to waste on pipe-dream projects. That's why observers took note when Mercedes unveiled the Ocean Drive four-door convertible concept at the 2007 Detroit Auto Show. Though obviously based on the company's big S-Class sedan, the Ocean Drive surely cost a mint to build, which implies it's really a prototype for yet another addition to the ever-expanding Mercedes lineup. A company press release tacitly confirmed that view by describing the Ocean Drive as a "unique luxury convertible design study [that] turns a 'dream car' vision into reality." Note the word vision. Several recent new Mercedes models have been previewed as thinly disguised "Vision" concepts. Though the Ocean Drive lacks that label, we take the press-release wording as a strong clue that you'll be able to buy something very much like it. The concept sure looked showroom-ready, but we're guessing that Mercedes will hold the production version to model-year 2011, if only to spotlight an expected mid-cycle freshening for the S-Class line, which was redesigned this year. Because the Ocean Drive name doesn't fit Mercedes' labeling scheme, expect a more prosaic title like "S550 CS," for "Cabriolet Sedan" or maybe S550 SC. As always with Mercedes, the number on the badge will relate to engine size. The concept was based on the lush S600 sedan and its 510-horsepower turbocharged 6.0-liter V-12, but Mercedes would probably also offer an S550 version with a normally aspirated 5.5-liter V-8 tuned for around 400 horsepower. Hey, even plutocrats need something to aspire to.