if your car is new, and you havn't been messing with your headlights (i.e. taking them apart and painting the housing black) then you should be able to take it to the dealership and replace it. most likely the glue isn't on tight enough so water gets in, causing condensation. i tinted my headlights and the glue on the passenger-side headlight didn't seal tight enough so every time i wash my car, i get condensation. it goes away after a few days, but it leaves nasty water marks.