Agreed. Your table structure doesn't allow for any history though. The way you have it, there is no field to archive a vehicle and I'd suspect wherever you do business, the law would require you retain information for a set period of time. If not, you should, just to CYA. Likely you don't care to keep historical plate numbers, but just in case - you can't do that either.
From an ex meck-u-nick
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.