Don't bother with the police. Getting run over by a car is a "police incident", but almost getting run over is generally not.

As mentioned above, a GoPro/Contour might be a good idea if there are a lot of dinks in your area. Take down license plate numbers, and think how you might be able to get even if in the future you should happen to encounter the vehicle parked in a lonely wooded area sometime, with nobody around to see you... nothing illegal of course