I regularly pass some old geezer wearing a police style cap (like armed response would wear) on the A38 near Burton on Trent driving what I can only assume is a wannabe cop car.
He used to drive a white Terrano with stripes down the side but no police markings and (strangely) a blue light bar. I first thought it looked a bit dodgy when I noticed he was using a Sat Nav (every time I saw him in virtually the same location) and he had bin bags taped to the inside of his back windows to black them out - it was always really early morning when I saw him too and he never had a passenger/partner.
He now drives a Pathy and if it had Police written down the side it would be identical to the real thing - chevrons on the back, blue led light bar and the works. The thing is, I thought it was illegal to have a blue light on your car even if it wasn't operational.
Mind you, I've not seen him for a while, so maybe he's been nicked. In any case, if/when I do see him, I always make a point of accelerating as fast as possible past him just to pee him off. Silly old fool.