Ok, so probably I'll go and talk to my installer to see if he has an idea about what to do. Probably he will need to give a look at the car....
I simply hope I am not giving up some specific feature/on screen info by replacing the head unit by Audi with my Empeg.
I can't find any specific info on the Audi's website. Do you know if there's any good resource on line about Audi's pre-installed head units and stereo systems?