[KevinH1990]

It is installed and working. It turns out that the red wire with the black stripe (Pin A1 on the 3-wire black connector) is the power for the button illumination on the memory control. That explains why the system worked when I used both 5V and 12V power to that wire. I will need to connect it to Bridge Plug BS7. I originally connected it 12V power under the seat, but that was constantly on.

I will be coming back to this project in a few months. During my part acquisition process, I obtained these metal-plated control levers:
I think they may be from a 996.

I'm considering having them re-plated as I think that will look better than the silver-painted handles I'm currently using. So at a minimum I will be doing a cosmetic update and addressing the illumination issue. If I can find more information about the mirror function, I'll address that at the same time.