997 side/ind/fog light lens deposit

[PaddyZulu]

My recently acquired car has this on both sides, does anyone know what has caused it ?, is it common ?, and I would appreciate how I could fix it please.

Tried Duxback headlamp cleaner, which worked a treat on bringing back to life the headlamps as they had yellowed and gone dull, alas not so for the lower lamp lenses.

Thanks in advance.

[Chubbyross]

My only guess would be a ceramic coating of some sort.

[PaddyZulu]

Appreciate your reply thanks.

[mk1coopers]

In the picture it looks like it’s on the inside, if it’s on the outside it may be a factory UV coating that’s failed, you may have to sand it off and re-polish / re-protect with a headlight restoring kit.

[PaddyZulu]

Definitely on the outside, thanks for your reply, guess I’m going to have to get gritting