For 2000, the 2.8 Sedan and 2.8 Avant get an optional five-speed manual transmission. Audi's quattro all-wheel-drive system is optional on the 2.8 Sedan and standard on all of the remaining models. This system constantly monitors the grip of the tires. When one of them starts to lose traction, the quattro system automatically applies power to the tires with the most adhesion to the road surface., , What Edmunds Says, Refined and luxurious, the all-weather A6 family offers a satisfying alternative to the BMW 5 Series or Mercedes E-Class -- the 2.7T is our favorite., , Pros, New selection of engines, well-appointed interior, all-wheel-drive stability., , Cons, Non-linear steering, questionable exterior styling, 4.2 model's molded rear seat.