I dont think that a car without an MoT pings the pinger in a police car.
It may or may not show up on ANPR , but I was certainly pulled for exactly that reason late on a Christmas eve two or three years back .
I had submitted my car for MOT a few days before it was due to expire , but due to work being needed , parts having to be ordered and the garage being busy at that time of year , the old MOT expired whilst the car was in their care .
Since , in the absence of my car , I was using the train to get to work , the garage had closed by the time I was able to collect my newly MOT'd car off their forecourt on Christmas eve ( I was on good terms with the garage and they were happy for my to return and pay once they were open again ) .
Getting into Aberdeen at about 11:30 pm , I was welcomed to the city by blue flashing lights and , on stopping , the policeman took on an accusing tone , asking if I knew why they had stopped me ! Of course , I was at a loss , and it was only when I was in the back seat of the police car and questioned about the car's MOT status that the penny dropped
At first , I don't think they believed me that the car had passed its test only a few hours earlier .
To top things off , the garage had not left the new MOT certificate in the car when they left it out for me to collect , but , to satisfy myself the test had been carried out , I had visited the MOT info website and printed off confirmation that the car had passed that evening . Thankfully , this was accepted and we were able to continue our journey after an amicable parting .
To summarise , I'm not sure whether MOT status will 'ping' on an ANPR check , but it most certainly can be queried via a PNC enquiry - which is what I think the cops did - only there is a delay ( overnight ? ) before the VOSA computer updates the PNC with the most recent data .