When I had my MR2 Turbo I was in the right hand lane overtaking on A4 fairly late in the evening when a car flew up behind me doing 100mph+. I pulled in after passing the car in front and the speeding guy from behind pulled alongside and then slowed to my speed. Annoyingly there was a slowish moving car a distance in front of me in the middle lane so I had the choice, slow down or speed up... obviously in an MR2 Turbo I chose the later option. After flooring it, indicating and pulling out in front of what I affectionately call "The ****" he decides that once I was doing (some speed) it would be a good time to turn on his police lights! He then pulled up along side me as I was pulling over, looked at me, wagged a finger and sped off.
To be honest, there was only one of them in the undercover car so he was probably off duty, but I think my affectionate name for him is appropriate.
EDIT: Typos.