Morimoto RetroRubber Butyl Sealant Black Universal
Now, this stuff is very cool. There are plenty of you out there who at some point have or will modify your lights to black out the lenses simply because it is a cleaner look. The problem is re-assembly. The glue or cement used to bond lights together is some pretty gnarly stuff. It's usually a thick black silicone stuff that sticks onto everything and it creates a mess.
You can avoid all of this by getting the Morimoto RetroRubber Butyl Sealant. With this sealant, you can just pull the length needed, apply it to your application, and it instantly bonds without creating too much of a mess. Should be good enough to do a pair of headlights.But you can also use for other lighting purposes as well.
This is their black compound and will work well for those of you who are going to modify your lights to black out the housings, to add a Morimoto LED kit, or if you simply want to prevent any more moisture from generating on the inside of your lights.