The MagnaFlow 2008-2012 Audi S5 Sport Series Cat-Back Performance Exhaust System enhances your 4.2L 2008-2012 Audi S5 with an aggressive character that is sure to help you stand out from the other Audi S5 you encounter on the street. With its 2.5in. diameter fast-flowing mandrel bent main piping that passes through 3 Straight-Through mufflers before ending in a Quad Split Rear exit with 3.5in. Polished Welded-On Double Wall Angle Cut Folded Edge tips, this dyno-proven Audi S5 exhaust system refuses to be ignored. As such, 16598 is tuned to produce our powerful, resonant signature exhaust note at Aggressive exterior and Moderate interior sound levels, so please check to ensure compliance with local noise regulations. The system's cat-back design replaces all your import's stock exhaust components from the catalytic converter on back. Extensive 3D scanning and CNC precision robotic manufacturing techniques are used to ensure that your exhaust system fits perfectly with just a simple do-it-yourself installation process. The durable, corrosion resistant stainless steel construction of 16598 is backed by MagnaFlow's limited lifetime warranty.