They may well have access to the DVLA system now to register the car (saves them going and queing up at the PO or DVLA office) so this won't take long. Surely they are waiting until Sep 1st to register it?
IIRC, main dealers can 'pre-register' with the DVLA, so that the official 'date of reg' can be a few days ahead.
VWmaindealer might be able to confirm though.
Supaguard shouldn't take too long to do, can't guarantee that it will be applied with much love though.........
By the sounds of some of the feedback . . . . about 30 minutes . . . .
