New OEM from Ford supposedly has a hard coating/film on the exterior of the lense that the aftermarket units do no have. Still, if they are the original spec. headlamps they will fog. I found a aftermarket coating that applied at the lube place I used for our Escort, but I wouldn't swear by them. It does have a lifetime warranty on the reapplication of the coating. Costs about $75 each headlight. Kinda high, but it is guaranteed, so it's a one time pay and good for as long as you own the car...not bad if you lamp assembly isn't fogged up.