The two best Audi forums are:
Audiworld
Quattroworld
Most of us old Audiworld regulars have defected to Quattroworld. Check either site for the TT forum, then remember that search is your friend.
quattroworld.com Forums: TT Mk1
And you can also check your local region on those sites for others in your area that might be able to help out.
quattroworld.com Forums: Central
Being a long time Audi nut, I can tell you that these are the best places to find the answer to any Audi question