Hi Bin for about 2 months proud owner of an Audi Type 89 Coupè. The car has already been transplanted by the previous owner a complete stainless steel system from Kat von Supersport. Only where from the sound is it really dull white not if it is normal with the 2.8 V6 but I would have expected that he has a crisper sound. Does anyone have any experience with the supersport system? Gruss Tim