Originally Posted by simonas
After a little of research, for the future retrofitters: if you want to replace or install the head-up display, you must remove the windshield and/or replace it with a special one that has a PVB foil lining inside of it. As far as I could get from the manuals, most of the control modules are within the unit and need no add-ons (except a new light switch). The part connects to Terminal 30, Terminal 31 and Display and Control CAN.
So for retrofitting you need not only the part itself and a new light switch, but also a new windshield.
Resource: The 2012 Audi A7 Occupant Protection, Infotainment, Climate Control, and Head-Up Display
I still don't know how to figure out the VAG-COM stuff and if anyone would help me, I would highly appreciate.
From what I've learned over the two and a half years I have owned my A7 is that retrofitting options simply does not make sense.
First of all the cost of the parts is prohibitive, even if you can do the work yourself.
The other issue is that practically every part has coding, and the codes have a great interdependence on what other items are installed in the vehicle. Some of the coding is accessible and can be changed with the VAG-COM cable and software but there is a bunch of stuff that is not accessible with it. On top of that, there is very little info on what the codes supposed to be.
The central computer at Audi AG keeps the info on every vehicle based on its serial number. If you take the car in for service, it is hooked up to the computer and most codes get reset to their original values.
I found that I can trade my car up to a newer model with the options I want for less money than the parts to do the upgrade would cost, and that way it is guaranteed to work.
If you search the forums, you will find a number of sob-stories from people who spent countless hours (besides the money for the parts) trying to make a modification to work and have never succeeded.
By the way, I do have the night vision camera system in my car. It is a great conversation piece to show it to somebody, very impressive but it is a totally useless thing and a complete waste of money. My next A7 will not have it.