[DaveNP]

I think the key here was that you let the cat out of the bag when you let on that the car was already in France, if the DVLA issued documents for cars that couldn't be checked on they'd end up at risk of being accused of facilitating crooks selling ringers. The travellers get round it by just sending in the form as if they and the car do live at the address they put on the form, if DVLA ever do check up they're not there and they don't care anyway.