If pursuit can be eased back without fear that the individual will be completely lost, while giving the police an ability to intercept the car even after the contact is lost, the one fleeing would need to abandon the car for another ASAP to keep from being tracked—and the GPS would convey immediately when and where the car slows down to consider such activity. It may not solve everything, but it does seem like a useful tool in some instances.
A useful tool at what cost? You’d have to put one of these on almost every car to be of any use.
besides it would put the helicopters out of business.