i washed my coupe yesterday and stood back to take it all in and realised that one headlight lense is duller then the other. on close inpection the dull one looks like some kind of laquer type of thing is peeling off, so i was wondering if the lights have some kina of coating on them.

You can use some 2000 grit wet+dry to blend it but use it lightly, then apply a few light coats of acryllic lacquer the finish will be good but not quite as good as the original light was.