Private plate transfer to car with private plate

[rfisher]

What happens when you buy a car with a private plate on it and put your own plate on it?

Does DVLA automatically send the previous owner a V778 retention document or does the previous owner lose his plate?

[rfisher]

So the private plate on the car has to be taken off, a random plate assigned by DVLA, then the random plate goes back to oblivion and the new owner's private plate gets assigned?

The whole system is patronising IMHO.

Why can't you just own a plate instead of paying for the right to have it put on a car that you don't even have to own?