Is he speeding, driving dangerously and/or without due care and attention? Revving the engine? Driving aggressively? Then the best advice I can give is: get a camera. The cops tend to ignore it (it seems), unless there's a collision or altercation involving reports of assault. That's why there's so many pricks on our roads, unfortunately. At the very least, it may be re-assuring to know certain insurers regularly browse these sites? ;)
The most indecisive driver in history.
This person in a Ford Focus is sat at a junction. It's a left turn only. There's many many many many times when there's no traffic coming from their right nut nope they sit there holding up traffic behind them as they wait on god knows what.
If you're seeing things then you shouldn't be behind the wheel!
WEll done for defusing the situation with your mature converation skills.