Although we can't tell exactly what happened before the dashcam started recording, the well-dressed driver apparently felt he was being followed too closely, so he stopped his car in the roadway, calmly got out and gave our dashcam-wielding driver a stare that will probably help him or her avoid tailgating in the future. Now there are plenty of methods get someone to stop tailgating you, but this could be one of the gutsiest moves we've even seen.
We wouldn't exactly recommend pulling this move (unless you plan on getting run over or provoking a fight), but you can see what transpires in the video below.
UPDATE: As there usually is with these types of events, there's more to the story. Thankfully, there's also a pre-altercation video to go with it. We've added it below, so check it out.