I installed a cheep e-bay wireless camera / monitor on my ole 30ft Mirada. I wired it into the running lights for power.
I ultimately rewired it to do away with the wireless.
I tow a Camry on a dolly and have TPMS sensors in the dolly tires and in the rear tires of the Camry. This allowed me to monitor the dolly and Camry tires while traveling. Unfortunately, the wireless camera transmitter was interfering with the TPMS transmitters and I wasn't getting reliable tire pressures. After I discovered the interference problem, I re-wired the camera and did away with the wireless part.
Rear View Camera – 2001 Coachmen Mirada 300QB
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The rear view use is somewhat limited. I can keep an eye on the toad, make sure the toad lights work. Its good when we back into a parking spot as I adjusted it so I just barely see my rear bumper, so I know where I'm at. AND, on the very rare occasion when I pass someone on the road, I use the mirrors before changing lanes, but also verify in the monitor that the toad is clear also.