I think I'd have some fun with this one in court. I lived on the Eastside back in the late 80s and 90s and beat every speeding ticket. I got four tickets in the first month I had my 300 ZX-TT, so I hired an attorney to handle them (I could have lost my license!). I kept the documentation and memorized his techniques then defended four or so more myself over the years. I had an infamous "ticket.doc" on the network at work on how to defend tickets in court. Back then, you'd do the following (going from memory here):
1. Request written copies of all documentation on the radar unit used (calibration, etc.)
2. Request the officer to be present (half the time they won't show up, instant dismissal)
3. Do not request the radar expert to be present (if you do and they show up, you're dead meat)
4. Get your story straight (fallback strategy)
Then you play rope-a-dope once in the actual court. A minor violation like this is a joke to them, so the judges are looking for a reason to dismiss and get on to the meatier cases. No documentation before the court date means instant dismissal (BTDT). Radar expert doesn't show up and the judge asks you if you requested him, say yes (BTDT). Documentation shows up or is promised *at* the court date, ask for a continuance and that the court pay for the remainder of your case because of their error, including any attorney fees (BTDT, my attorney used this one).
In your particular case, I'd lay an extra trap. Make no mention of the video. You were not in violation *before* the speed limit sign and the cop was sitting at the sign. If the cop doesn't show up, you're golden. If he does, then you ask him where you were relative to him when he clocked you. If he says words to the effect of "coming at me" then, boom, you show the video to the judge. Instant dismissal ... and you'll probably have the judge yell at the cop (BTDT). As a backup, I'd probably bring along evidence showing the deceleration rate of a Model 3 and compare it to the distance given by the cop.
I guess it depends on how flexible your work is on whether you want to challenge in court or not. I was in software development back then and no one cared if you were in the office or not, just whether you got your work done in time. Gone for half a day, no problem.
Edit: the post by
@Skipdd reminded me of the details of the "continuance" case I mentioned. When we went into court, my attorney said, "oh, the judge and I go to the same tennis club". I thought, piece o' cake on this one, considering that the court provided no radar records, my attorney knows the judge, etc. No so! When my attorney said his standard, "there's no evidence that the radar used was calibrated and certified for use, therefore the radar reading should be thrown out and the case dismissed", the judge replied, "no, we'll provide you with the required documentation". What??? My attorney got a little mad and said something to the effect of, "due to an error by the prosecution, I request that the court pay my client's exorbitant legal fees from here on out". That got the judge a bit cranky, he grumbled a little, then said, "DISMISSED". It was all academic sparring between two attorneys.