I just recently had a fog light blow out. I ordered a new bulb over the net. However now that I have looked at it I noticed alot of water/condensation inside the fog light. Think Ford would repair this under warranty since it appears that the bulb blew due to water leaking through the seal?
I'm sure they'll warranty it, but they'll give you a new set up that will do the same thing sooner or later. I got sick of it too, and pulled mine out, and put RTV sealant on the seam between the lens, and plastic body. Just be sure you dry them out good first. (hair dryer). Just fix yours up. I've had no problems since.