Clio Headlight Mist Problem

My wife has a 2004 Clio 1500 dci, the problem is both headlights have started to mist over on the outside at the top where the indicator is, it is exactly like overspray but the car has had no new paint, i have tried white spirit, petrol, and turps but they will not remove it, has anyone got/had the same problem or idea'show to remove it.
Cheers, Dave