I cobbled an inexpensive system together using parts from ebay a couple years ago. I stuck with 1.2ghz in hopes of minimizing interference from the 2.4ghz transmitters. I mounted the transmitters inside a cabinet which puts them right behind the truck's rear window and the receiver is above the headliner in the cab. Maybe 4 feet between them and nothing but wood, filon, glass, and whatever the headliner is made of to block the signal. Should work great, right? I still have problems with interference at times. Generally brief but annoying when one of the spots is where you're parked in a rest area. I'm currently leaning toward bringing a cable out the rear of the headliner and hard wiring the cameras. I already use a window boot so that's not a bad option. Although, I do wonder if those 'Direct from China' radios could be part of my problem... :)