Here I'm getting ready to glass in a "cover" for the roll bar. A piece of 1 1/2" PVC pipe fits right around the roll bar. With trial and error I cut the pipe at a rather aggressive angle such that it lay flat against the trunk wall and fit tight against the roll bar. The plan is to use this pipe as a mold for the fiberglass, then remove the pipe itself. This should make for a slightly oversized "tunnel" for the roll bar to feed through.