Make it law that the supplier of car insurance issues a plastic folder, maybe on dayglow, which would fit in the corner of your windscreen, it would hold your tax disc, and display enough detail of the car insurance & MOT for police and wardens to immediately tell whether a car is legal or not.
Make failure to display punishable by a heavy fine. Make displaying false and inaccurate info punishable by a heavy fine.
Then slowly things would change and only legal cars would be on the road.
Why does this idea matter?
This would cut down the number of vehicles on the road,
This would increase the income from fines for illegal use of vehicles on the road
This would cut down the number of accidents involving uninsured vehicles
This would make the roads safer for legal drivers