Last winter, I nearly got taken off my bike on a roundabout on a cold frosty morning. I was already on the roundabout, turning right, when a car came from my left. Didn't see me, and only my luck saved the day. Well you wouldn't see me, would you, when your driver side window is completely frosted up and your windscreen has only a small portion cleared.
I don't normally condone violence, but I could perfectly understand if someone more volatile than me (!!) dragged people like that from their car and showed them the error of their ways.