Hi mate
I still have this as a problem even after going back to my dealer 3 times. They have even drilled small holes behind the lamps but I still get condensation. I think it is to do with the cheap plastic they use and it not being sealed correctly. I have got really quite irate with the dealer recently and will be going back again soon!!
Let me know if you have any better luck.
barrywalsh@firenet.uk.net
Barry