Audi S4/S5 B9 Non Sport Diff models - Resonated (Quieter) Cat-Back Exhaust System with Quad GT-90 Titanium Trims Model_(8P) 2.0 TFSI 2WD (5 Door) 2004-12 If you are unfamiliar as

If you are unfamiliar as to why this kit is so important

Fitment is for motorsport and off road use only as this system removes the GPF filter

If your friends went through this

This M4-inspired conversion would make the perfect addition to any 425d M-Sport

Audi S4/S5 B9 Non Sport Diff models - Resonated (Quieter) Cat-Back Exhaust System with Quad GT-90 Titanium Trims Model_(8P) 2.0 TFSI 2WD (5 Door) 2004-12 If you are unfamiliar asOur range of Cat Back systems are perfectly suited to cater for anyone looking to improve their sound and aesthetics, designed as a direct replacement for the original system, available in multiple configurations enabling the owner to choose the increase in volume of their exhaust and or add a more suitably aggressive tone. All our products are made from 304L Aircraft Grade stainless steel. This quality material will ensure that your Cat Back system