I rang my local VW dealer a couple weeks back to ask if I had to notify them that I had changed my numberplate and they couldn't give me an answer, so I asked them to update my reg on their computer systems and today I received a new roadside assistance card with the new plate on it, not sure if it really matters that much but if I hadn't I think I would have had to quote old VRN if I ever called them out which I have already forgotten.