my front lights get a little "condensation" on the insides every so often, not really enough to worry myself over, if i did id be an ill man with the cars ive had
my old celica used to leak water into the rear cluster, i took the cluster off and silicon sealed it to high hell and it still did it. In the end i drilled about 5 3mm holes as drain points and after heavy rain would run my fingers over the holes to draw all the water out. japcrap eh