Yeah I had to have a tracker fitted to a car about 20 years ago otherwise it wasn't insured for theft, the bloke who fitted it however said a typical smack head wouldn't touch that sort of car as they know it's tracked and the chances are it would be stolen to order from within the car industry.
Apparently there's only about 5 or 6 places they can hide the tracker unit and the garage guys know where to look so take it half a mile round the corner then strip the unit out so when plod turns up he finds it by the side of the road
Trackers are only any good if the car is seen when stolen, or the knob has left it parked up to see if it is tracked and found, then it is only if the tracking company are on the ball. Some do get caught through them though, some get missed or shipped out quickly.
Back years ago, the garage next to my Fathers was raided, he had just, ahem... repaired a damaged top of the range Range Rover in a rare colour, the only other one in London was stolen shortly before, I cannot say who it belonged to.
Plod took it and him away, but could find absolutely nothing to link the two. while they were so eager on the Range Rover, he used his phone call to get several Police Sierras and Metros removed from the premises, all damaged, but also out on hire through a cheap car rental company
.
The moral of the story, if they want your car no matter who, where and when, they will get it.