When I was buying my GSi, the guy was friends with the Ultratune mechanic next to his work. They did a pinkslip on the car. Didn't think much of it at all, until I got familiar with the car, and realised they must have just gone crazy ticking things and not checking them.
For instance, they said that both the tyres and seatbelts were fine. When in fact the front 2 tyres are nearly bald, and the drivers side pre-tensioner is borked.
The guy fixing my car atm.. (although he's an asshole, he's good at what he does) says all ultratunes are dodgy.