Can a car be registered in 2 countries at the same time?

[Marcellus]

As some know I'm moving to France soon and it's been suggested it's better to change my car to a French registration (insurance, road tax etc etc etc).

If I were to what would happen to my UK registration number?

And would my vin code be related to my UK reg in the UK and French reg in France?

Taking it further, what would stop me from driving it on UK plates in France and French plates in the UK?

[Le TVR]

When you import the car and register it here they should inform dvla that it has been permanently exported.
(IIRC you must complete registration within a few months of import.)
Only the French plate is then valid.

I imported my TVR here many years ago and it sometimes goes back to the UK on French plates no problem.

[flemke]

Normally when you import a car within the EU you have to hand in to the new registration authority the old registration, which they forward to the old authority.
Upon export, your UK reg number is put on the shelf. If you were to re-register the car in the UK in future, you would get back your old reg #.