I just recently traded in my '01 GTI for an '07 A4 2.0L Turbo, and have found it to be the biggest nightmare of my life. I bought it, and within 9 days I found myself stuck on the side of the freeway with a broken timing belt.
Initially thinking it was the battery, I had a friend come over to try to jump start the car to no avail, and then I had to get a tow truck to take it back to the city to get it checked out. Found out it was a broken timing belt, and being that it was an interference motor, it could have cracked the walls; thankfully it didn't, but some of the pistons are damaged and it needs some work.
HOW DOES an '07 A4 die within 2 years! I should have just kept the GTI, it had given me noooooo issues!
I HATE IT!
I thought that the newer Audi's (post 2004) are all timing chains rather than belts.
I'm sorry to hear about your luck, it makes me wonder why the 2.0L Turbo VW's have better reliability, I'd imagine that they'd be identical.