Nothing so far. These cars have come a long way since the 80's.
Pros:
Comfortable ride, decent fuel economy, lots of features for the money, reliable.
Cons: Handling a bit sloppy on the curves, transmission is old design from the early 90's, and does not utilize the engine's power as efficiently as it should.
I still have my Audi, but use this car for business. I am happy with my decision to buy this car due to the price ($14,400 with sunroof, traction control, and anti lock brakes when the 07's were available) and its reliability.
This is an update from the original poster. 28,200 miles with no issues other than a blown fuse (covered under warranty).