Don't want to put a damper on TDi, but we went to TDi North with a mates dc5, to get springs and a gruppe m induciton kit.
The kit was fitted, and ratted/squeeked when driving, which he had to fix himself, after paying a huge amount across the part and fitting. On top of that, the springs they ordered were wrong, and will have to be re-ordered (still not resolved, about 2 months ago now). Then on the way back home, they phoned to tell us to pull over and check the wheel nuts, as they weren't sure they'd tightened them (already done about 200 miles!)
Not a great writeup I know, and I have heard a lot of good things about them, but that would put me off...
Dave