i know this is a noobie question but would 18" wheels that came from an audi b5 1.8t fit on my tt?

 

Not without an adapter... TT and A3 are 5x100, most of the rest of the Audi line are 5x112.

 

well he has 18" hp evo rims and he's selling them for cheap ....where can i get the adapters and how much would it cost me?

 

ECStuning and other's have them. They run about $160 for a pair, you'll need two sets. They works as spacers too, so you'll need to see if you have sufficient offset in the wheels in order to fit them without rubbing.