Yes, driving and gesticulating in an offensive and threatening manner can be interpreted in many, many different ways I've discovered.
For instance, you demonstrate aggression like that to the humvee escorts in Baghdad, they will oblige you by shooting you with automatic fire, without ever stopping to ask what you really meant.
_________________________
The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)