its happened to me and si many of times...the worst we have experienced is.. 1. overtake someone on a vespa moped, he then decides he doesnt like it, catches us up again, gives us the finger etc...we indicate to turn off to our house, he then decides he's going to try and follow us...so gunned it off, and ended up taking a 15 minute D-tour home... 2. Another one, some imigrant in an old battered kia hatchback, we overtake like you do....doesnt like it, comes back past, and for the next 15 minutes, decides to drive slap bang down the middle of a dual carriageway so we cant pass, and if you attempted it he would just swerve into you... one was a chav, the other was a forigeiner...