Probably because the tyres were routinely changed, occassionally because the plates were changed ..
This goes to the domain of "who cares about plates | body VIN | engine VIN | tyre relationships".
Even 3 weeks ago, someone rolled up to our building parking lot at night here in long Island and stole plates off a car. We had it on camera.
The cops had them arrested the next day because they drove by one of thousands of plate scanners with the stolen plates fitted on a car.
Basically even every police vehicle has plate scanners on its rear pointed forwards into both lanes.