Some say the heat cracks are caused by using the foglamps in wet weather. I'm not buying this theory because my truck is never driven in the rain and I still get the heat cracks.

The halogen bulb just makes too much heat for the plastic lenses, it's that simple. To prove my point, I intentionally refrained from using my foglights for five months after they were replaced under warranty last September. Within a month after I started to use them again, tiny cracks started to appear. Prior to turning on the foglamps again, they continued to look brand new. Now, four months later, both of them are full of cracks.

Ford has to know there is a problem with the lenses on the 2001 and newer Lightnings. If they don't, it's only because other Lightning owners are not forcing the issue on them and are either living with the cracked lenses or replacing them on their own nickel. As long as my truck is under warranty, I have absolutely no intention of paying for new lenses.