I just put in a new pair of headlights (whole glass housings), and there's a little bit of condensation in the bottom part of the inside. I'm pretty sure that the bulbs don't form an air-tight seal with the little plastic holding rings, but what's making moisture form? Is this going to damage the bulbs?

Can I just air out the lights really well and put a bead of silicone around the seam of the glass/plastic? How does one go about fixing this problem? thanks

 

Yeah you could probably do that. Or open up the housing and re-seal it again.

 

I have no idea what the water is from, but I am having the same problem with my tail lights, they fill with water and I can't figure out where or or how

 

Seal the edges with silicon, not too much-- should be ok.