Installing roof rack to fiberglass camper shell

Hey all. I just picked up a leer xq shell. I'm looking to install a roof rack, probably from a junkyard. From what I can tell, the racks there are installed with short screws, which I don't think I can do with a fiberglass shell. I'm guessing I'll need to use bolts, and drill a clean hole through and use a nut and washer on the other side? I'm not sure. Has anyone done this or have any recommendations on how I can do this? Thanks!

 

did you find an answer to this? I'm curious to know if I can safely install and use a roof rack on a leer xq it doesn't have one.