Drilled the hole on the exhaust fan. It was the easiest place to mount the camera with the least number of problems.

Hole on the inside for the cable to pass.

Got the camera installed. I used rivets to attach the mount. Not shown is the hole sealed up.

Monitor on the inside of the van. I need to get a splitter so I can also use it in the cab. That and I have to get 12v up there.

Right now the wiring is a bit of a mess and I have yet to wire in a switch to activate it. So for now I have to manually connect the system to one of the 12v batteries I keep back there.
Good field of view and should work for both backing up and for seeing who might be around the back while camping.