Audi S6 – Photo Gallery: Montreal, Quebec – Quick – name the midsize luxury sedan that sells the best in most global markets. Here’s a hint – it’s from a German manufacturer. BMW 3 Series? Mercedes-Benz E-Class? Wrong. It’s the Audi A6. If you had no clue, don’t worry – you’re not alone. Even Audi of America’s Executive Vice President, Johan de Nysschen, admits that his company’s product is “under-recognized and under-appreciated in the U.S.” To fix that problem, 19 new or redesigned models will be launched in the near future, all intended to nail down the attention, and hopefully the buying dollars of U.S. car shoppers. One of them is the 450-horsepower 2007 Audi S6 sedan.