Audi S4 B9 Non sport Diff models - Non-Resonated (Louder) Cat-Back with Quad Polished Trims M135i GPF-Back (Box Delete) Test Results:

GPF-Back (Box Delete) Test Results:

With a name like Trackslag

Matched with the upgraded resonators and rear box

8dB on the static 4

The Cobra Sport system really improves the drivability of this car and takes it to the next level"

Audi S4 B9 Non sport Diff models - Non-Resonated (Louder) Cat-Back with Quad Polished Trims M135i GPF-Back (Box Delete) Test Results:Our 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