I know from personal experience the extent of ANPR. Some years ago I was (falsely) accused by a "witness" (not the actual owner) of bumping into a car in a motorway car park in North Wales. I got the call some weeks later and they told me the time it was supposed to have happened. I wasn't even in the car park at that time, I was asked where I was and I said I'd left about an hour beforehand, it was motorway all the way, I was coming back to Teesside so I'd be maybe 60 miles down the road. I was asked if I'd give permission for a search of ANPR data, and I agreed. I got a call back a day or two later corroborating (more or less, the time must have been maybe 15 minutes out), they could tell exactly where I was at the time I gave them. Still doesn't answer the question of why I was picked out by somebody with (I'm told) no interest in the incident, they couldn't have known me from Adam (I was on my way home from Aberystwyth to Billingham), and my son had a time-stamped phone video of me at the service station with baby starlings feeding from my hand, my car was in the background and nowhere near a car of the description I was supposed to have bumped into while parking.