There is vent in the rear...a little "U" shaped rubber hose fits
into the vent nozzle. You can try blowing into that vent with
hair dryer, I suppose. You can also try using the hair dryer
direct to the front of the outter lens in hopes the heat will
cause the condensation to evaporate. These are after-the-fact
cures. You may still need to resolve how and why it occured...
as it is likely it will reappear if the conditions are right (or
One could also yank the light assembly and seal the perimeter
of the headlight (where the outer lens joins the gray housing)
with silicone. I used windshield silicone first...as it is more
viscous and allows the goo to seep into the tiny crevices and
nooks. This was followed by regular, clear, RTV silicone.
This sealing exercise was done when I retrofitted E55 bixenon
HID into my E320 so I had everything all apart anyway....and
was in the process of closing and sealing everything up again.