This morning, just by the main Heathrow exit, someone in a dark Jag drifted over into the lane I was in, not indicating as he did so. I was right behind him, travelling slightly faster, so ducked to the inside to overtake. As I did so, he indicated to move back left, saw me, sounded his horn and then flashed his headlights. I gave him something inbetween a cheery wave and the bird and carried on. I looked again and he'd put his blues on (hidden in the grill) and chased me. Fark. I slowed down until he caught me up and then looked over to see him making 'slow down' signs. But that was it. I was just approaching the M4 bus lane so pulled into that and made off. He can't have been traffic because I don't think I would have got away with it. Also his driving was pretty bad. So who could it have been, and are they likely to follow up anything?