I have the IBall 5.8GHz
wireless backup camera, which is supposed to be immune to the bluetooth device interference that plagued their earlier model. I only use it for hitching, so I don't know if it would also work for backing a trailer into a campsite. My rig is 33 ft long so I'm thinking that would be a lot of ground for a good wireless signal to cover. I'm going to try it out on my next trip, just to see how I do.
On the back of my tow vehicle, however, it works just fine. The image is in color and is pretty clear, certainly large enough and clear enough for hitching. All you do is stick the camera to the rear of your vehicle, point it toward your hitch ball, turn it on, and plug the receiver/screen in a 12v outlet in your truck. The screen is on a nice goose-neck mount so you can adjust it to any viewing angle and it's pretty solid. The image will occasionally get a quick line or two of static during backing, but nothing that interferes with coupling a trailer. Both the camera and receiving unit are small enough to store in my center console with tons of room to spare.
If you get this unit, a couple of tips - since the camera unit is battery operated, the fuller the charge, the better its signal to the screen in your vehicle. And second, the magnet strip on the camera base is okay, but I'm going to upgrade to a heavier magnet to increase picture stability and ensure the camera stays put when moving my truck. Hope this helps.