I had a standard license plate type wire into my trailer for almost a year now. after a few issues here and there, and finally the lens fogging up, I just pulled it off, and found a wireless one with good reviews on amazon for $170. Hopefully it serves me better than the last one. prior to that, I had the same camera, with a wireless transmitter/reciever into my stereo display that I picked up for $50 or so, but it was iffy when it would/wouldn't work. I'm guessing the range was an issue, although when it did work, it was a good, solid picture.
Hopefully going to a wireless made for an RV/trailer will solve my issues.
2010 sunset trail ST26RK, 2012 Nissan Titan SV crew cab, equalizer hitch