I installed a digital Voyager backup camera from rvcams.com. Never have experienced any interference. Before I installed it I tested its range and was able to pick up the video signal half a block away. I used the center rear marker light for camera power, which means I have to turn on the lights to use it. The only downsides are its high cost and the fact that is it has limited vertical field of view. I can't simultaneously use it to view the traffic behind me and still see the trailer hitch ball - have to point it one way or the other.
