Have you done a headlight projector retrofit project only to find a mysterious burn or blister spot near the projector shroud a few months later? This is a known issue in the retrofitter community that doesn’t really have a specific name but is commonly referred to as blistering, sun burn or paint bubbling. What happens is if there is a ledge below the projector lens, when the hot sun hits it just right day after day at a specific angle there is a bit of a sweet spot where the projector and sun turn into a magnifying glass burning ants situation:
Generally, this is only an issue if you’ve opened the headlight and painted that specific spot (that used to be chrome originally). If you paint it black or green or blue or any color you run the risk of experiencing the sun blistering effect like these:
CHROME DOESN’T BUBBLE! If you leave the chrome there on the shroud you won’t experience the blistering! Of course if you don’t want the chrome there because you want a cool black-out look you need to get creative. Some of the companies that specialize in projector retrofits have developed a method to leave the portion that is susceptible to sun blistering chrome, and paint everything around it.
Here’s another version where the entire inside of the projector shroud was left the OEM chrome on a 2015 Dodge Ram with factory projectors. If that inside portion was painted purple like the rest of the shroud, over time it would blister from the sun and a magnifying glass effect.