We chose to add a backup camera to our 19'
Scamp that is hardwired to the monitor in the rear-view mirror. It is mounted against the trailer just above the spare tire. We also have a camera focused on the bed of the truck, wired to the same monitor. There is a power button in the dashboard and a switch in the glove box (to switch between cameras). He wiring harness is a four-prong that runs along with the
Scamp harness and plugs in next to it under the bumper of the truck.
I like being able to check the bed of the truck while traveling to check the load (both the hitch and anything else we have tied down back there) and to use the backup camera as an auxiliary rearview. Caveat: backup cameras visually distort as do passenger-side rearview mirrors. Objects in the camera are WAY CLOSER than they appear (which also means that you won't see that Maserati coming up your $#s until it's too late), but it nonetheless offers another piece of information when passing and merging.