The flexible solar panels aren't as effective as rigid ones for numerous reasons, plus, they're more expensive. I don't know what your roof is like but you might want to check out what I did with mine, which is pretty convoluted. I found a Renogy 100w panel that's only 19.6" wide, thereby minimizing the curve issue:
https://www.google.com/search?q=reno...hrome&ie=UTF-8
I ended up mounting it with DIY mounts made out of aluminum angle. Using two per each end, I was able to tilt them to match the curve of my roof. My roof's curve was pretty gentle but I could have handled more. If your roof curve is severe, you could use more, shorter mounts to follow the curve.
Check out my thread, especially the last post for a photo:
https://www.sportsmobileforum.com/fo...top-26528.html
Note that I didn't use Riv Nuts in the fiberglass, but used 3m VHB mounting tape to mount the panel. I did use Riv Nuts in the panel frame but you can use nuts and bolts.