Audi S5 Avant by ABT Sportsline comes with more power, some exterior enhancements, and a few extras on the inside ...

The 2012 Audi S4 exists to satisfy power-hungry customers who find the pedestrian A4 - and its 2.0-liter turbo four - inadequate. Instead, the S4 is packed with a supercharged 3.0-liter V-6-engine ...

Still, the A4's quality and features justified its relatively high price. The S4, Audi's iconic compact performance sedan, has attributes to suit diverse preferences. As the "S" suggests ...