I went through Amidon myself in August of 2003. I don't remember the patrol car, maybe because I was fretting about running out of gas at the time -- especially once I realized there was no place to buy gas in Amidon.
Anyway, I recently ran across someone else's photographs of the "speed trap": http://www.sorabji.com/2002/road_trip/north_dakota/amidon
Barrington, Rhode Island
When visiting the Presidential Range in New Hampshire, consider renting my house in nearby Bethel, Maine: http://www.vrbo.com/42141