Adhesive for steel solar brackets to aluminum roofs

All very helpful! Indeed with the aluminum roof it's just stretched over the frame, and is loose. The sail thought opened my eyes on this that I may very well want to screw these in, as I will be traveling at up to 80mph, but I have no idea to know where the frame cross members are... I need to see if I can track down a blueprint somehow. And a wiring diagram to make sure I'm not drilling into a loom of wiring... argh. It's never easy, is it?