The problem with roof mounted panels is that you have to park in the sun. If you don't mind your Airstream acting like an oven this is fine. I prefer a portable system so I can park in the shade, if available, and keep my panels in the sun. I can also manually track them directly at the sun for maximum efficiency. I have a cheap ($150) 55W system that includes panels, controller, 50' cables, battery clips, inverter, etc that I got at Costco and it works fine for keeping the batteries topped off. At that price I figure if the panels get stolen, it's no big loss. I've used them for about a year and a half and have been happy with them. I keep everything in a dufflebag, and it takes me about 10 minutes to set them up at camp. The nice thing is I don't have to run the generator to charge the batteries.
"THE OLDER I GET, THE BETTER I WAS"