It was a pain to run the video cable all the way back. If I had to do it again I'd buy this cable:Chris. Yes I got the 12v from the taillight. It is a bear. The guy I asked to install wanted $400. Plus extra for some other service. My fingers were raw for a coup!e days but I think it was worth it in the end for me.
Saves either the trouble of powering the camera from anywhere in the rear or it saves you the trouble of tapping the relay for the reverse trigger behind the dash.
My Joying unit doesn't like getting power from the reverse tail light. It wants power before the trigger so tapping to the 12v accessory connector on the right rear solves that.