02/2012 X5 35d M57Y CPO 119K miles NOKIAN WR G3 30K miles
Maximize time with high beams to heat and evaporate the moisture. There are vents in the assembly.
Operating the headlight warms the assembly, expanding the air and venting excess volume/pressure. When the headlight is shut off the assembly cools, contracting the enclosed air and drawing humid environmental in to equalize the pressure. The humidity moisture condenses in the interior and the droplets have no way to run out and accumulate for you to see the ‘wetness’.I would be more concerned about how water got there in the first place. Seems to me that, if not corrected, it will happen again.