VW UK will have some say...but you'd like to think it's the same rules across the whole "Dealer" network.
The only reason I can think of Dealers making it a bit more difficult is to save themselves some money and put people off.
VW Kings Lynn have been nothing but helpful so far, just waiting on the booking date to come through, they have impressed me no end so far, I took the GTI in for a DSG Service yesterday, they gave me a Courtesy car for free, washed and hoovered the car, done a health check report (sent me a video via email), they also done the coil packs, as when I booked it in (1st time with them), it was not listed as being carried out previously.
So for a £179 DSG Service I think the "Customer Service" was very good!
It's in for the Cambelt and Waterpump next week, hopefully they can keep up the consistency :)