The question is exactly what you mean by "scare some sense into them" and just how far you intend going with it. I have, on occasions, been known to do little shoulder feigns and whatever else to make myself appear unpredictable if I feel the situation requires it, but normally I just claim as much space as I feel I need in the lane. That seems to work best.

However, that's generally as far as I ever take things. If they really bug me, as Mr Fix said, it isn't really worth the stress of trying to win a "road rage" (i.e. being a dickhead) battle with them, so I generally don't bother wasting my time. If they do something really nasty or dangerous, I'll just pay a visit to the cops on my way home.