it is not cheap but 01audiS4 has MTM exhaust on his audi and it sounds amazing. He gets compliments pretty often. When I was looking at clips on you tube MTM’s setup sounded the best to my ears. I know you guys have different engines but from the research I did when I was looking into the V8 Audi’s MTM’s exhaust is well liked, But in all honesty it is difficult to make one sound bad.
Ao God, Miltek > * for the B6 S4. Sounds like God with no horrid interior noise. I HIGHLY recomend it. Not cheap though, getting a high quality, good sounding, but not “loud” exhaust that isn’t custom isn’t going to be cheap.
it all comes down to if you plan on doing down pipes. i am not. so i just ordered a fast intentions cat back.
i didnt want it too loud cause its my daily driver but i really love the exhaust champion motorsports did for the s4. too bad it never went into production…
edit: i was also dead set on the awe non res but ive been on the list waiting for it to come off backorder since i bought my s4 in may. not worth the wait i really enjoy the F.I. sound. cant wait for it to get here…
as for miltek the resonated cat back everyone complains is too quiet so if you really want to do miltek you should go non-res but that just seemed a little too loud.
also you may want to check out labree they are pricey but nice (however danny who is the owner of fast intentions used to work for labree and actually designed the s4 exhaust)
lastly motorklasse has a wicked awesome sound but i dont think they make them anymore you would have to find a used setup…