Alright... making progress.
The rear pocket did end up as a good fit, so I ordered it from GM parts direct. It just got here today..... the wire harness was on back order because they did not have anyone to make it for them. I think I have it worked out but need verification..
I've attached this pick to make it easy for you guys to understand what I want to do.
Will this work without blowing fuses or hurting the electrical system?
Basically tapping into another light source for the license plate light power.