Don,
Those are good points for sure.
Years ago in 1965 I was coming across what we call the Winters Cut Off from Vacaville to Dunnigan and a CHP car followed me almost the entire distance and finally turned on the red light. He came up to the car and asked me why I never slowed down as he saw me look in the rear view mirror several times and knew that I was aware of him following me. I told him the speed limit was 65 and that was what my speedometer read. Then I remembered that I had changed wheels and my speedometer was reading slow and I told the officer so. He asked if I could prove it and as luck would have it, I had the receipt for the new gear with me as I was going to pick it up in Redding on my way home. He then took me to the patrol car and showed me what his radar read and told me that he wasn't going to ticket me as obviously I wasn't trying to lie about it and I had looked and seen him several times. So I got off with a warning to remember that my speedometer was reading less than I was going. I got the gear as I came through Redding and came straight home and put it in. My last ticket was by a Redding cop for doing 37 in a 35 zone at 3 AM in 1969 as I had gone downtown to send a bad circuit pack back to the labs. I and the cop were the only cars on that mile long stretch they call Miracle Mile and the judge threw the ticket out.
Ron