I'm trying to find a suitable clear plastic cover for my MotorTrike Adventure fog lights which sit very low to the ground, they keep getting cracked/broken by small stones thrown up from the pavement. I've tried the 3" lampguards from Big-Bike parts which I RTV'ed to the fiberglass surrounding these fog lights but they eventually melt into the foglight due the heat from the halogen bulb. I suppose that if I could find a 4" round clear plastic piece, I could RTV that to the fiberglass and it would keep the plastic cover a bit further away from the lamp. I've looked on-line for 4" clearance light covers but so far can't find any that are clear. Any suggestions?