You are not supposed to have condensation in the headlight, but you are also not supposed to aim a high pressure washer at the vent.

Many owners have had headlights replaced for condensation when they don't dry out by themselves, but before going to the dealer check and see whether you are contributing to it during the wash.

Also, are you sure the headlight washers are leaking and that it isn't residual water from the wash?

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue