Luxury cars were easier to choose back in the past. Earlier, people who wanted comfort and class bought a Mercedes. Those who preferred a more sporty, but still comfortable car went for a BMW. Now, Audi has entered the luxury race as well, with the A6. Can it beat the long-time top-class leaders from Stuttgart and Munich?drive it! compares the Audi A6, Mercedes E-Class and the BMW 5, all equipped with similar 6-cylinder 300 horsepower engines. Watch drive it! to find out which of the luxury sedans gets the checkered flag.