Good Q. My point is that I would punt on the wiring. You're right, that has the potential to be a very big PITA. The workshop manual has the electrical schematics. I would then just run my own lines directly down the roof (after liner is gone) from the mirror to the fin tapping into those PIN points. Rather than rehashing how to do this, do an Advanced Search on the guy who installed an Alibaba type Dashcam. He did his own pin rewiring. It's VERY intimidating if never done before. With an inexpensive pin removing tool and a pin connection tool, you can just jack into it. I'm not an engineer, I went to school for Accounting! And sadly, failed there so no longer an accountant<g>. Get the wire colors on both sides and just make a run for it. A more straight forward approach would be to replace the entire harness with a proper one, but my post was that (in my opinion) that may be a harder problem to solve.

 

Would something like this be an option for a retrofit for clear sight

AUTO-VOX V5PRO OEM Mirror Dash cam 1080P Rear View Mirror Camera with Night Vision

On amazon

 

@dahaggis - Try this thread. May help you a bit more: Link.