Scirocco Register

Anyone know what it is?

The black stuff is unpainted - it's just black plastic. (Unless you have a later black car eg GTII, then the paint code would be the same as your car.)

That's weird, cos mine has worn through in places and is showing white underneath. Perhaps it's some kind of plastic coating/lacquer?

That said, I have been thinking about painting the body kit the same colour as the car.

could just be that a previous owner has painted them. you can get a plastic spray for refinishing plastic bodyparts, which comes in a variety of colours and textures to match original. i thought it was made by autobrite, but i can't find it on their website. halfords do a black "bumper paint" but i've got no idea what it is like. alternatively you could go for plastic primer then satin or gloss lack colour and laquer

My theory is the black arch kit on these cars is not like the arch kit you get on something like a Mk2 Golf which is solid plastic.

It has a coating on it and does seem to have a light coloured inner colour, maybe a primer. My theory is the coating is highly flexible to take a beating.

You can see where on my old Mk2 Scirocco GT the door sag has worn through exposing the lighter colour but darker underneath. When I removed the kit on this car it actually tore a scab of this coating off where the kit joined like a heavy duty sticker tearing. Even my GT2 which has painted arch kit has worn through with door sag to this light colour probably primer. Not sure what to suggest with painting or actually just replacing? It seems to have only worn here on this kit and some bits out of sight. Where is yours worn?