I've been trying to pin down the parts required but those who do the retro fitting keep it close to their chests and if you call Audi parts, they just laugh at you..!
All I know is, one retro fitter confirmed he would have to scan the car prior to doing any fitting to see what modules are installed first - I guess that's to determine what additional parts are needed.
I would guess, as my car doesn't have the folding mirrors (should be standard in my eyes) it would need the modules, motors and new door switch and trim. To date, I've been quoted £1,600 which is pretty steep!