I built a back up camera system in '97 when I put the largest camper Lance sold onto my 1 ton Dually Dodge/Cummins with service body. Bought a 5 inch B&W monitor and CCD camera for $40. I rewired the CRT yoke to reverse the scan and mounted the monitor upside down. The effect was to give me a mirror view (left right reversal) instead of a standard camera view. It came with a plug in the wall power supply (18 VDC) but it worked fine on 12VDC. It worked like an electronic rearview mirror. The camera mounts under the rear roof overhang of the camper.
I have nearly 50 years experience backing up to trailers. It has gotten about as easy as it is going to get. I am pretty darned good at it without the mirror. I am a pretty good marksman without sights on the gun too but way better with them. Likewise, the mirror is a sure kill and easily gets you dead on first time nearly every time. I have relatively poor visibility without it on the 1 ton. Just bought a draw bar and ball for the new 3/4 ton but haven't backed it up to a trailer yet. Remains to be seen how easy it will be. As it is a crew cab 4x4 (taller) the visibility is not so great.
Thanks for the link, I was blissfully ignorant of the inexpensive Wally World unit. I'll have to take a look. I purposely did not get the back up cam on the truck because I want to do my own. Ditto the nav system. I want to choose my own GPS unit which may ba a laptop with GPS card. The Super Duty F-250 has a neat rectangular depression in the center of the top of the dash that looks to be just about perfect for some custom equipment and will only obscure the view of the hood, not the road as I am not vertically challenged. There is room above the rear view mirror to place an LCD screen.
Thanks again for the link, I gotta check that out.
Pat