i bought an import from Motorprovider
I found the local VW dealer in Telford very helpful, I took a copy of the V5 and they sent the details to VW at Milton Keynes for warranty registration.
I rang VW assist last week and my car is even covered for 12 months european breakdown etc.
Talk to the service guys at the dealers - they will want any warranty work and your ongoing custom - there is no reason for them to not to welcome you as a customer. It's understandable when they sales guys turn their backs but this is not my experience.