We wanted to monitor our boat behind the fifth wheel so we bought this system:
http://www.rearviewsafety.com/produc...5th-wheel.html
It is $300, kind of pricey, but much cheaper than the equivalent system from CW. Theirs lists for $749 and is essentially the same.
We are very happy with it, it's been on the fifth wheel for 3 years now and works just like advertised. One issue we did have was where to install a 7" monitor in the truck where it is "out of the way" yet visible when in use. I wound up installing velcro on the back of the existing rear view mirror and I just velcro the rear view monitor over the truck mirror when in use and remove it when we are not towing.
Over the time we've had it, I've grown used to having it not only when the boat is behind us, but also when we are towing without the boat. It's really nice to see what's directly behind us, something we can't do with mirrors. An added feature is the microphone/audio. No longer can my DW mumble things under her breath. I can hear everything she says while watching her in "full living color"
Hmmmmm maybe I should disconnect the monitor when she is back there?????