The original machine screws that held the luggage rack mounting hardware on the roof were not strong enough to hold the panels, so I drilled larger holes in the roof and used brass bolts. I had to cut through the ceiling liner to get at the bolts from inside the truck (see photos below). Not a pretty sight, but who cares. It was worth it.
For almost any kind of solar electric power system, you need some way to store the power when the sun is not out, and this usually means a battery. You also need some way to regulate the current going to the battery, and a diode to keep current from going back through the cells. I used an inexpensive ($49) electronic solar charge controller/voltage regulator made by Specialty Concepts, Inc.
The charge controller (above) was easily mounted to the side rail in the back of the truck with two machine screws. I could also see the charge light from anywhere. Notice the in-line fuse on the wire – very important.
This battery was kept under the bed next to the fridge. Deep cycle marine/rv batteries come with threaded posts that make it simple to hook up multiple wires.The cover was made from a plastic storage box. I had a long wire with in in-line cigarette lighter type connector on the end that could hook up to a laptop computer or light, and sit in a camp chair away from the vehicle, or in the tent. I also charged video camera batteries, cell phone batteries, and flashlight batteries off the system. All you need are the right adapters or connectors, which are not hard to find.