Pschmidt, glad to hear you reported the incident. I'm also glad to hear it happened at low speed, at least there is less likelihood of injury.
If you want to push it further contact your County Council member -- they always like a good incident to get energized and with only a year to go until elections they may be even more energized. I don't know where you were, but if you were near a school, rec center or senior citizen residence make sure you play up the danger to such innocent victims by agressive driving. Sometimes making a complaint is all in the packaging!
I would stick to the route and keep an eye out. Obviously if he behaves in a reckless or agressive manner again hop off the road (sidewalk or wherever you can get quickly) and call tyhe cops right away. With 1 report filed a second complaint will be serious. Its a lot to ask, but if you catch the plate of one or two cars that might have witnessed the event so much the better.