#8 power, #9 for the ground? Take pics for me, I need to do the same thing. There should be other options up there, I remember Volt guys getting power from the purple wire for the map lights.

 

Looks like VT (violet) with the light green tracer is 5amp switched with ignition power and black will be ground at the mirror module.

 

Do you have an aftermarket backup cam - rear view mirror ? I'm thinking of installing an aftermarket touch screen dual camera recording back up cam to the rear view mirror. Thanks for the wiring schematics I'll be using that, saved me some time so thanks!