I also have used 2-part clear epoxy glue. I applied it with a toothpick. You need to work fast because the glue gets stringy really quick. I learned the hard way when I got glue strings on my chrome bumper/grill. To be on the safe side, I mask everything except the headlights. Epoxy glue is not as good as clear lenses but it does give the headlights some depth.