A few of our club members have a discoloration (yellowing) with the headlamps one's a Jag the others a Nissan Primera but i'm sure its not just applicable to these particular vehicles. The lenses appear to of a plastic material rather than glass so a kind of perspex I suppose . Various treatments ie Brasso, scratch cleaners etc have been tried but all with limited effect.Apart from renewing the lenses at a considerable expense, and as it could become an MOT failure in time has anyone any thoughts or remedies on the matter. PS The photo is obviously how they should be!
I have had the same problem on my Subaru for which I use Maguire's Plastic polish. internet is best for buying this product as its not held by your average car accessory shop. But it does require a bit of elbow grease.