Does anybody have experience with riv-nuts or nut-serts (same thing I think). I am thinking it might be easier to but three 1/4-20 nut-serts into the top frame tubes at the rear of the window opening, then loctite a 1/4-20 stud into them. This would give me a permanent spot to mount the lexan on when I needed to, and they would not be nearly as obvious as a peice of plate like my first idea. The topframe tubes are relatively thin wall---too thin to tap, but with a nut-sert locked into them it might work fine.