GR...
Well done fella!
JLW, if you have a drill box, or a local hardware store that sells drills. Use yours/ their drill index box. Find a hole that the screw will barely fit into, then go down two drill bit sizes and you have the perfect sized bit. (By the way Finish Line screws will work quite well.)
ALWAYS start a hole in a painted fiberglass body with a bit at least two sizes smaller than your final hole is to be. This will eliminate any chance of chipping!
Now, to keep a screw tight in fiberglass that "wont" vibrate out or simply work loose, put a couple of drops of Loctite on it before final installation. It will never work loose until you want it to!
DV...The above works great on boats too!
Tonneau cover snaps, convertible top snaps, fender mirrors, etc... Yup--this works.