Re: moisture build up inside the fog light
Several years ago the rear lens assemblies on the 964 cars filled with water. They ultimately decided that it was a design flaw. If it's not too much trouble can you remove the assembly intact from the vehicle and inspect it for where the intrusion is coming from? Maybe a poorly installed gasket? Is there a vent hole somewhere on the bottom of the assy that is blocked? Personally, I would rather look at it myself to figure out the 'why' of it than to go back to a dealership for a solution. I think we all know their first answer will be "that's normal." The problem with moisure obviously is that it will start to breakdown the silver reflectance coatings in there as well as to impact the electrical conductivity of the bulbs and wiring. Look for the drain hole after searching out the gasket installation job.
Dan