last May, got stopped doing 78 in a 35. (missed seeing the sign slowing down from 55)...
anyways, asked to see the calibration records on the radar gun and was told I could subpena them. Then asked to see the serial number of the radar gun and the vehicle VIN number to be sure that they were the same on what I would be subpenaing. Was told that I had no right to see those by the officer. I argued, he refused.
Went to court, and subpenaed the audio tape. Case was thrown out by a very mad judge ( mad at the officer for allowing me to get off ). I left, and have since slowed down somewhat.