Today I cut the slots in the seat for the seatbelts and am concerned that over time the fiberglass seat could cut/weaken the belts. I realize the plans call for the edges of fiberglass to be sanded smooth, it has been my experience that the stuff can still cut the heck out of most things (skin included). I think some sort of protection should be in place, perhaps the same stuff we use to cover the edges of holes in aluminum through which wires pass.