You guys got it pretty much covered.
Lately, I've been seeing a bit of moisture inside both of my headlight assemblies. I have a pretty good feeling it's seeping in through the black rubber plugs that seal the holes I had to drill in the back of the plastic caps that cover the low beam access holes for the HID wires to pass through. They're visibly not sealing completely tight against the plastic like they did when they were brand new, so I have a feeling that's the culprit. I already took one light apart, added a generous amount of silicon around the entire perimiter of the light when I put it back together as well as completely sealing that rubber plug with more silicon - no more moisture in that light. Now I just have to completely seal the other one and I'll be back in business. Anyway, just something to think about...