Mercedes-Benz’s CLS 500 arrived on the market seven years ago as a brilliant optical illusion with an oxymoronic classification. Its low, descending lines fooled the viewer into thinking this four-door sedan was a two-door coupe. Jaguar, Porsche, Aston Martin, BMW, and even Hyundai eventually followed Mercedes-Benz into the four-door-coupe segment. Now comes the Audi A7 (www.audiusa.com). It is actually a five-door coupe, because it is a hatchback, which Audi calls a sportback. We call the $60,000 vehicle a sleek fastback and an immediate classic that offers sophisticated architecture, an impeccable interior, and all the convenience and flexibility that comes with a fifth door and a spacious cargo area.