But if you don't buy the PDC control unit - then if you select reverse won't the parking PDC graphics cover up your camera picture going in via AUX-in.
I have a genuine Audi RVC camera in the house, but don't really wan't to spend even more money on a new boot microswitch handle and number plate light strip + getting it painted. So might try dremelling a square aperture for it in the existing handle.
Wist I'd never started this retrofit - turning out to be too expensive.