Older? You're still a pup.
Actually, I think that if you went to Audio King in Minnetonka, there would be some great installers. That's where the best ones go, because that's where the rich people live. You can tell them you're doing it yourself, and what pieces do you need. They will probably let you talk to someone from the install bays, I'm sure they've seen lots of Audi's come in. Best Buy and Circuit City are to be avoided with your Baby, but AK is pretty good really.
Bring that thing over so we can get to work! Also - I saw the TT install page - if you haven't contacted him yet - do so! Any hints will save a lot of time. I expect to get mine in my eclipse in about 30 minutes, but we may spend all day on yours being careful since you don't know how it comes apart yet.