I recommend you use a custom camera like this:
https://www.amazon.co.uk/s?k=xc90+ca...f=nb_sb_noss_2
It fits in place for one of the plate lights, and includes a LED light.
You can then just hook it up to the wireless transmitter and follow the OEM wiring path.
There are lots of good spots near the REM - you'll see the flat spots where the accessory modules would attach.