What? No they do not. The plates stay with the person not the car. You can transfer the plates from car to car as well.
> Do you live in a place where one must obtain new plates immediately after purchasing a car?
Where do you live that you don't????
Are you sure that in your state plates transfer with the car? What state is that, because I would like to look that up.
http://drivinglaws.aaa.com/tag/transfer-of-plates/