I had a similar problem with condensation when i installed my LED angel bulbs. I struggled to put the cover back on and when i finally wrestled it into place. i noticed that i had lost one of my clasps that holds the cover in place( thanks to Brut force and ignorance) . Problem was you cant order the clasp alone from BMW as it comes as part of a new headlight. So long story short i did my best to avoided car washes and rain for over a week till managed to find the clasp on ebay. by then i had condensation, xenon bulb was no longer working in that headlight. it really sucked a lot. I gave it some time and the headlight eventually dried out in my garage with the odd bit of help from a hairdryer. all of a sudden the error message on the dash diapered and my headlight came back to life and its been happy ever after.