Got them from Chase Tyres in Cannock, there's a few sellers on fleabay just check the size (especially offset). There's a few mm (4 ish) gap between wheel and caliper.
Centre cap is actually a sticker on a blank but it looks so well
I didn't bother to buy the expensive Audi caps
(note if ou do want to put Audi caps in don't use the metal ring
as they just clip in without it)