Quote:

Some sort of "back off" hand menuver would be good.



Bennybmn,

I agree with you, a "back off" hand (finger) manoeuver indicating what you are hypothetically going to do to them works most of the time. You can always claim you were scratching your back if the need arises.
They just don't know how mean or crazy you may be.
Another is to progressively slow down (while watching your mirrors) and irritate them, that normally catches their attention.