I also have an M3 cab and that too has an AV option on the SatNav. It needed a seperate loom to be attached to the TV tuner to give you the inputs however. A plug-in also gave me 'TV in motion' which would be nice in the Gallardo... for my passenger. I imagine the Audi unit would need much the same? Wouldn't like to guess where the TV tuner is though?
Because I have the BMW, I'm used to Parking Distance Control and it's never failed me. Unfortunately, I'm in the habit of not judging by site and I've nearly forgotten a few times already in the Gallardo.

I suppose I'd give the camera a go if it was a cleaner install?