as a British owned French registered garage who import U.K registered cars and put them onto French plates,we may be able to shed a little light on the whole vehicle registration thing.If the vehicle is to be permantly resident in France it must comply with French law which states: Full French insurance is required(carte vert) any french insurance company will tell you that the vehicle must be on French plates within 6 months It must have a Controle Technique(a u.k mot is not valid) The vehicle must be registered in the Dept it is resident in There is currently a "clamp down" in progress over with regard to vehicles not registered on the French system (for the reason that it must be traceable by the authorities)