My son's car's plastic headlight cover leaks when it rains, thus the halogen bulbs explode. He has taken the cover off and there are no cracks. The water is coming through where the lens/clear plastic part connects to back (interior) part of the cover. What kind of sealer/glue can he use to seal it up to keep the rain from seeping in?

A clear silicone will work well. Stay away from glue.

Silicone will remain flexible during the heat of the summer and the chill of the winter. The problem with glue is it will prohibit you from disassembling the headlight if you should need to in the future.

A side note on installing halogen bulbs. DO NOT touch the bulb with your hand or fingers. Use a clean rag or paper towel to remove the bulb from the container and install it. The oil from your hand can cause the bulb to explode.

NC