Bought this unit from ebay for 500$ , thought i can retrofit it in my Audi Q7. Dealer was able to program radio and bluetooth, nothing else worked for me.
Navigation is displaying : Navigation initializing...Please wait. dealer opened the housing to verify if hard drive is connected but still have the same error.
Finally Audi dealer conclude that this unit will never fit in my car since audi A6 and Q7 don't have the same canbus system and this explains why my rear camera and parking aid never displays in my screen.

So i'm selling this unit for parts since i can't guarantee that navigation will work (audi said that i need a navigation SD card or DVD to reset everything)
Pm me if you want pictures