I don't know how things are in Blighty, but here in France certain naughty fellows play a game called 'doublage'. The chances of being physically stopped by the police on the highway are practically zero, but the chances of being zapped by a speed camera are extremely high, so 'doublage' involves finding an image on the internet of a similar model and colour car to yours and having some plates made with the other car's registration number. Then it's the other poor blighter who receives the speeding summons in the post. Arguing it wasn't you or your car takes a lot of time and effort, you can even pay a little extra on your car insurance to cover legal costs if such an occurrence arises. Best just to mask your registration number.