Martin Underwood wrote to uk.transport.london on Sat, 25 Jun 2005:

It always intrigues me to look at other countries' ways of solving problems
(especially if I think our way of doing it is better!!) - in America, France
and Germany, someone obviously made a conscious decision that it was a good
idea to change a car's registration number whenever the car changed hands,
rather than either the car keeping the same number throughout its life or
else the driver keeping the same number throughout his life.

Indeed, the present system in some countries is that the car must change
its registration number whenever the owner moves, never mind when the
car changes hands!
--
"Mrs Redboots"
http://www.amsmyth.demon.co.uk/
Website updated 23 May 2005