Hi Brett -
Ray Christopher has on several occasions fitted an Audi trans to GTD - although his are a little different to standard. I'm sure he'd be happy to discuss with you re any difficulties if you like. He does not use the forum (or pc's much!) so if interested let me know and I'll ask him to contact you.
ps - give me a call when you get a chance as I need to pick your brains re the wiring of a Ford Concept Car.... I'll pm you my number.