I hear good things about the MIJ guys and will be contacting them about a quiet exhaust for me too. But I have also been recommended to the guy that used to be Dubsport and then went to or ran Blueflame. He does custom exhausts and his work is well known. I know one of the Jabba guys had a custom pipe on his A3tdi with real nice fat downturned rear pipes. It looks top notch.
You will find many a custom tuning exhaust place in yellow pages, powerflow agents too, but be careful, best to find someone who is familiar with your car (eg MIJ) and can also offer back up if it does nto work out as you expect. For example the Miltek back up is ledgendary, if a pipe is noisy or boomy you need someone to sort it out. Many places that do custom exhausts buy off the shelf stainless boxes and cobble a system together, wihtout really addressing customer needs. also be careful fo the stainless quality, there is a two basic types, one that it easuier to work with but which goes brown and yucky with heat (4600??) and another which is more tricky but looks nicer (309??/) . not sure fo tjhe numbers but one begins with 4 the other with 3 I think!
If you are unsure, maybe try a system wiht tailpipe options (eg supersprint) or get an off the shelf system adn have a local specialist change the tailpipe for you...?
