Good evening to all. Has anyone had the annoying problem of having fog or driving lights develop a whitish coat on the inside of the lens, and how (if possible) were you able to clear it up?

Sand and buff the outside, it's like a free hour of labor in the shop

So the problem is on the outside surface of the lens and not on the inside? Please note that these are glass lenses and not plastic.

This is usually caused by a deteriorated seal. If you are referring to the OE fog lights that most of the older XJ's have (like mine), they are very simple to clean but, you'll want to use something mild such as window cleaner that's safe for tinted windows (non-amonia based) because the coating on the inside of the lens could be damaged.

Make sure you have a firm grip on the lens while you're loosening the screws. The glass is slippery and extremely fragile. I accidently broke one of mine and had to replace both because the new ones have slightly different looking lenses.

Anyway............when you're done, a thin bead of clear silicone around the mating edge will help prevent leaks.

Thanks for the info! The lamps are not OEM, but I guess the procedure is basically the same. I have seen this before on a set of out-of-the-box fog lights; that's why I decided to run this thread & see if anyone had the same experience. It's pretty annoying to see lenses that are supposed to be crystal-clear, only to find this crap inside a sealed lens. Aarrgh!