MagnaFlow SYS C/B 09 Audi S5 4.2L V8 CoupeThe MagnaFlow 2008 2012 Audi S5 Sport Series Cat Back Performance Exhaust System 16598 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