New Instructions from the DVLA
"In order to assist other motorists in identifying potentially
dangerous drivers, it's now compulsory for anyone with a lower
than average driving ability to display a warning flag
The flag (comprising of a red cross on a white background) will
be attached to the top of at least one door of their vehicle.
For drivers of exceptionally low ability, additional flags are
required."
At last some thing that will really work I think 4D