Check this further, of course, but I believe the Trackers are only fitted to
a) Vehicles belonging to disabled people who live at a Facility to ensure that Staff don’t illegally use the vehicle for their own purposes, rather than for the benefit of the Disabled person to whom the vehicle is registered; or
b) Vehicles registered to a person where Fraudulent use has previously been proven.
As I assume) neither case applies to your son, he can be assured that his vehicle will NOT have a Tracker.