I have a wireless camera on the back of my fiver. I take the rig out alone sometimes so its a big help. It wasn't cheap but had great reviews and I didn't want to deal with the wiring involved to get a signal wire all the way from the camera to an area where it would plug into the truck.
Granted, wired cameras have better pictures and are cheaper but for my needs, I did not want to invest the time it would take to wire it. Good luck with your choice. Phillip
http://www.amazon.com/Voyager-WVOS511-Observation-featuring-Technology/dp/B004RCSW4I/ref=sr_1_1?s=electronics&ie=UTF8&qid=1429967244&sr=1-1&keywords=Voyager+Wireless+Backup+Camera