If you’re a car shopper with a need for speed, the S6 is fitted with a 444-hp, turbo 2.9-liter V-6, while the performance RS 6 Avant wagon employs a twin-turbo 4.0-liter V-8 that delivers a ...

It’s important to carefully check the trims of the car you’re interested in to make sure that you’re getting the features you want, and aren’t overpaying for those you don’t want.