I had some guy going mental on the M6 once, it was the usual Sunday night traffic, a constant stream in all 3 lanes just about managing 80, despite being nothing more than a car length behind the car infront and so on as far as the eye could see. Even so, I still had some muppet sitting on my bumper flashing away, trying to undertake etc.

In the end he came up the inside and swerved across whilst his back wheel was level with my front bumper so I had to slam on the anchors.

Then he started doing it to the car infront of me What is the point really!