Personally, I think that the Tracker could be one of the biggest scams ever perpetrated.
I bought my silver Z3MC with Tracker fitted and when I took out a lifetime subscription, Tracker sent me the paperwork for the car which it had registered as a black Audi TT! I got the registrations correctly recorded.
A few years later, I had to have the car recovered from abroad and I never got any call from Tracker telling me that my car had been moved over 500miles on the back of a truck or for its 200mile journey on the truck in the UK. The only ways that you can test if Tracker is monitoring your car is either find a bit of hilly straight road and let the car roll downhill for as long as you can without the key in the ignition, or push the car in a car park without the key in the ignition. This test failed to produce a call from Tracker and when I enquired about my experiences, Tracker had no alerts for my car on its system.
So they sent out a technician to fit what they claim was another device to my car rather than make any attempt to find the supposed Tracker already fitted and test it etc. Tracker won't tell you whereabouts in the car they've fitted these devices so you've know way of knowing if a device has actually ever been fitted unless you stand over the fitter at the time. This makes me wonder if many vehicles allegedly fitted with Tracker actually have one at all. If your car gets stolen which supposedly has a Tracker and it is never alerted or traced, it's so easy to claim that the thieves are so bloody clever these days as the excuse why Tracker failed to prevent your loss or recover your car.
Tracker claims the accuracy of the system is that 2metres of movement without ignition should create an alert.