It's a pretty sure bet that these vehicles have no warrant of fitness and are not registered.
Rules are in place for reasons.
Have you noticed that drivers don't flash their lights at oncoming traffic when they see a police car on the side of the road or a speed camera as much as they used to?
Of course some still do but the attitudes of many road users have changed.
They are sick of hearing about speeding drivers causing accidents.
Loads of people out there probably know someone who knows someone who has been killed or seriously injured by irresponsible drivers.
The police are doing us a favour so if you see them out and about over the next few weeks don't abuse them, thank them.