Condensation Behind Headlight Cover

Just picked up a 2001 X5. With all the rain the last couple days I noticed for the first time condensation inside the passenger side headlight cover.

Rather than have a dealer spend hours pulling it apart to find the problem, has anyone experienced this and is it a complicated problem to fix?

See page 2 of the following post. If it's the same problem, the dealer said the casing was not completely airtight and fixed it for me. As soon as I pointed out the problem, they knew exactly what it was and fixed it immediately. Have not had same problem since. Good luck.

http://www.automotiveforums.com/vbulletin/showthread.php?t=184252