Nothing except one recall, where I had to stop by the dealer for ten minutes (during which, they also gave me a free car wash).
The first thing you will notice when you drive this car is that it is _extremely_ quick. The motor is a masterpiece; the car keeps up with many cars that advertise 300 hp. This is because the GTI's motor actually makes about 220 hp (it's advertised at 200 hp so its easier to market the VR6 in the R32) and it also has an extremely flat power curve. The driving dynamics are also phenomenal.
You don't buy cars just for the driving experience, though. Its refinement, especially the interior, is amazing. I test drove a BMW 3 series and I by far preferred the interior of the VW. The leather seats are especially impressive. They look fantastic and have considerable thigh and back support.
If I could, I'd give this car a 12 for comfort and performance.
My wife gave up her BMW 3 series to own this car. I know the feeling, when comparing the 2 cars it's just not even close. Reserve the BMWs to those who can't loosen their grip of status symbolism. Just a personal opinion, not trying to offend anyone. GTIs rule!