Nice Job, once you get the taste for it you cant stop. I have been doing retrofits since I first got a VAG back in about 2014.
So far I have retrofitted the following:
Door Handle illumination
Larger screen MIB1 (Cost of MIB2 was too much to...
Looks like it may have been fitted with either the Audi approved accessory or an aftermarket kit. Either one of them will not display on screen. You could get the car plugged in and see if you can access a parking module, if so then it may be a coding issue. As above do you have the parking...
Just completed this retrofit on mine. Drivers mirror already had the harness for the glass but the passenger side did not. Fitted the glasses and a loom to the passenger side mirror. Also had to run wires from the interior mirror to the connectors that meets the drivers and passenger door.
Unfortunately I am not familiar with the wiring changes on the b9. I would of just assumed you would need some wiring adaptors and then some coding carried out. Have you researched what needs to be done?
Please see this response I had in another post from member rawrmcrawrrawr.
5F - Adaptations
(15)-Vehicle function list BAP-interieur_light_0x08 = Activated (should be set as factory default)
(6)-Vehicle menu operation-menu_display_ambient_illumination = activated