Make the car into a robotic officer the as the human drives the car
around reading the tags that are within its line of sight and
correlating those tags with the type of car that they are registered
for. If there is a discrepancy between the information with the tag
and the actual physical type of vehicle the officers alerted about it
and can choose to investigate further or not.
Police cars are out in the community all the time and so you could
have an officer driving through a neighborhood and with the onboard
electronics scan pieces that it can see and correlate them with
locations known where those faces are normally seen. And if there's
something terribly out of whack the officer can be alerted and can
choose to investigate further
Invasive but they're already hidden amongst us so why not use them?