Hi,
I have a MK1 TT 225 Quattro Roadster.
I wrote a post a few years ago in response to another question. See here:
https://www.a2oc.net/community/index.php?threads/audi-tt-prospective-owner.39432/#post-349777
It looks quite stock but I have uprated brakes (pads), Milltek high flow cat and...