You might be amused at this then.
I was on the M6 minding my own business when an elderly gent in a BMW 5 series estate decided to park his car about a foot away from my boot at 70MPH. Now he could have overtaken the motorway was very quiet, but he decided instead to start flashing his lights and waving his fist!
He was so intent on playing his silly game that he failed to notice a black Skoda creeping up behind him. I couldn't see this as my rear view mirror was full of BMW 5 series bonnet. But my Daughter who was several hundred metres behind saw all the fun as it happened. suddenly (having seen enough I'd think) the Skoda turned on it's pretty blue lights and made a lot of noise
End result one 5 series 'aving a chat with the law. I suspect that tickets would have been written and a licence gained a few points.