Linford-quattro

Does anyone know what size center caps i need to order for my factory 20inch q5

I'm supposed to be picking up a q5 2.0 tdi automatic. But I've found nothing but endless horror storys on how weak the auto box is with the mechatronics failing. It's a facelift model (2012) so I'm hoping someone can tell me they made some sort of improvements from this year, because at the moment I'm thinking of getting the deposit back.