Without license plates how are they to tell what that terminal is connect to which white Ford Bronco they are inquiring about? Do they have to actually stop every white Ford Bronco they see so they can read the VIN or get the driver's ID?
The plate numbers are the least likely to be correct and the least likely mechanism of finding the vehicle in question. The plate number will help you discriminate between two vehicles, but it does not aid in the search. Likewise police helicopters have no problem following specific vehicles even though the plates cannot be read.
So, you are imagining a situation where there are two identical suspects that cannot be discriminated from each other using all the above information and it will somehow come down to the plate, and without it, police will be unable to proceed correctly?
Is this actually any different from a suspect on foot or a bicycle or skateboard?
They're an inappropriate solution to the technical problem they were invented for now that the internet exists. It used to be that police had limited ways to verify ownership of a vehicle, and a simple state owned database with state issued numbers was a useful tool to solve this problem.
Now.. the police have internet connected mobile terminals. I'm not sure a "number plate" is the right solution to any part of this problem anymore.