I was driving up the M5 last night when I was passed in lane 3 by a car doing about 75 mph followed inches behind by a guy in an Audi TT with headlamps on main beam and horn blaring. OK, so the guy in front of the Audi shouldn't have been in the outer lane as lane 2 was empty but what happened next was horrific. The Audi undertook then cut back in front of the other driver THEN BRAKED HARD.Chaos ensued as everyone else performed emergency stops (including trucks - I smelt the tyre smoke) and the Audi then accelerated and the other terrified driver swerved into lane 1. It didn't end there, the Audi driver slowed and then made repeated attempts to force the other driver onto the hard shoulder.
If it had been a motorcycle then the rider would most likely have been dead. If I'd had a dashboard camera then the Audi driver would have been facing a long stretch in jail.