so to clarify, i already bought the fitcamx camera, which you can see below. It looks completely built in, which I enjoy. However, it comes with a harness to plug into the auto-dimming mirror. i have no auto-dimming mirror but there is a bunch of wiring inside the black box for the front...
Did you ever find a wiring diagram for the pre-collision black box? There is obviously power and ground inside there without needed to go up the A-pillar. Just need to know which wire is which.