This is a blatant cross-post but it's this very thread that got me into looking for my rear view camera setup on the wife's 2009 Outback. Copied/pasted from Page 165 of the Mod of the Day thread.
The camera is a no-name
I think but the quality is stellar (matches my parent's IS250 and RX350. The wiring seemed very similar to OEM Pioneer.
Since the relatively thin camera wires are in the same accordion boot as the typically cut wires of this Legacy generation I put some foam tape around the edge that they’re getting cut on. Note, you HAVE to pull the roof liner down slightly to get to this hole. It seems many people put the tape on the upper hole thinking that’s the cutting culprit but …
at least on my 2009… the cut wires were from the lower hole.
I already had the panel off to fix/inspect the wiring so after that, mark your hole
Then cut and mount. For this hole I used a Christmas tree bit as this is hard plastic. I ran the wiring through the license plate light grommet.
I ran the wire down the passenger side of the car. It’s fairly straight forward.