you are a brave man... from the stories ive heard i would NOT want to fuck with the TUV
they make the SS seem like kittens
They are fucking insane. BUT, and this is a crucial but: I'm going to register it with the american military.
They are the people who passed my car with a complete aftermarket exhaust from the block back, aftermarket intake, and a d16y8 intake manifold. Oh, Did I forget to mention that I also had converted the OBD2 car to OBD1? heh. I asked the guy yesterday about turbos. He told me that it was OK as long as it wasn't leaking or anything like that.
But yeah, the TÃœV is insane. If you put the wrong oil filter, or stainless steel brake lines on, you're fucked. You'll get fined, then you have to replace them with the right ones. That's why everyone drives fast cars like the A6 here. It's too hard to make a car fast.