It's likely that more stops would occur until the offending cloned car is found. Whoever is using it is using false plates for a reason...
To avoid traffic offence prosecutions....
Could be a disqualified driver.......
As part of other activities....drugs,theft, etc.
ANPR will note the car every time it passes a camera.
In an ideal world a pattern may be found to help locate it......is it local or another area, for example.
Depends on the intel surrounding the car as to effort put in. Not perfect but the real world situation unfortunately.