Norm (Honda03842) attached a
solar panel to his
Scamp with VHB (Very High Bond) tape, and they've driven thousands of miles with it.
I keep my panel and
solar controller freestanding, and I wired them to a 7-pin receptacle so I can plug it to the trailer's pigtail after unplugging the pigtail from the tow vehicle. The
solar power runs through the trailer's converter and from there to the
battery. I could also have attached leads from the
solar controller directly to the
battery if I'd wanted to.