Today, I finally got some time. Here goes...
In post #11 above, you already ordered the USB mini (or micro or whatever your camera needs) 5v module.
And, you have removed the overhead console. The Torx screws (at least on mine) were T10, not T15.
I tapped directly into the power for the Homelink system. It seems to have its own fuse (good) and is on all of the time (bad). There is a red/ylw wire and a blk wire that supplies power to the system. Those are the ones you want. I tapped into them at the big connector for the complete overhead console. There is only one red/ylw and one black wire at this plug, you cannot go wrong. In fact, I removed the console and did all of my work on the bench.
Close-up of the red/ylw wire-
Since power is on all of the time to my new circuit, I added a switch-
Now, some of the reviewers on Amazon had some bad luck with their little 5v module. So, I put some spades on my new circuit and on to the 5v module (of course observing proper polarity). Now, if it fails, I can pull the old one out, fish the new one in and go.
I found it easier to remove the overhead console after first removing the little pop-out panel. But, getting those little wire connectors removed required a tiny straight blade screwdriver to depress the little keeper tab in. You don't have to do this, you can just remove the big main connector and call it good.