AWE Tuning Audi B7 S4 Track Edition Exhaust - Diamond Black TipsThe AWE B7 S4 Track Edition Exhaust is a direct bolt on Cat Back system that not only transforms the rear end of the car with it's menacing quad tips, but also turns heads with a deep muscular bass note. Each cat back system features an H Pipe crossover tube at the front to maximize exhaust scavenging for maximum power, as well as to take a harsh edge off the exhaust sounds. Tubing diameter for the entire system is 2. 25". Dig into the throttle and