I got caught once by a speed camera doing 65 in a 50 zone. The camera was in an unmarked van parked on the motorway lay-by (conveniently just after some temporary road works). A few days later the postman delivers a fine in the mail, so I ignored it as it wasn’t sent by recorded delivery (so no proof of receipt). Now, by law in the UK, the police have 21 days to inform you of the offence and three weeks later I get another letter from the cops informing me that I have an unpaid fine. So I write to them and tell them that I never received it and that I have no recollection of being on that road. They then send me photographic evidence of my car being caught at 65 mph in a 50 zone and that I am obliged, by law, to declare who was driving. I write back and inform them that it was so long ago I have no memory of who might have been the designated driver, let alone even being on that road, and that because more than 21 days have passed they have failed to inform me of the offence. They write back with some nonsense about having proof that the letter was sent, but I argue that this isn’t proof of receipt and that I’d be guessing if I declared who I think might have been driving that day. Result being that I never heard from them again.