I bought mine from VW just make sure you use the old screws in case the new ones are longer I have heard about people putting marks in there roofs as the screws that came with the holder where to long
 
Its a shame none of these holders are in black to match the Cupra R headlining.

What sort of material is the outside of the holder, is it sprayable?

yes it is sprayable:

DSC00677.jpg
 
i didn't spray it. i bought it pre-sprayed off a member on here - can't remember who though - hopefully they will join the thread to take the credit :)
 
the black dose look good. i want to get a sun glasses holder but can never find time to go to vw and get one. looked on e bay but theu are the same price so might as well get it from vw.
 
i can't see it being hard to paint, plastic primer and matt black spray; then a bit of modelling paint to do the red trim . sorted!