Gavin,

Im using a muffler called dynomax VT. Its a straight through muffler with a spring loaded butterfly, opens up according to exhaust backpressure.

This is my honest feedback. For now, my A4 sounds horrible at at throttle lift off because of the downpipe goes from 2 1/4 inch to a hollowed cat, goes back to 2 1/4 inch and then 3inch all the way back to a resonator and lastly the dynomax VT muffler. I think a mid section muffler will fix that and also when i install the psi turbo kit(proper 2.5inch downpipe), which hopefully be completed by next week when all the little thing arrived.

The butterfly inside has a tendency to rattle but it is not that obvious. Once I get that sorted, it should sound a lot better and with the mid section muffler, even more quieter. It does get loud @ WOT.

Here's a test done with a decibel meter :-



Here's one in car :-




If you're interested, text me



Danny