I have a Tracking device in the Motorhome. (GPS Live, Linked to a Giff-Gaff Sim) Recently it was in for some Body repair, following being abused by a lady driver whilst parked!. Fascinating watching it move from the repair shop to the paint shop and back then outside when they put the graphics back on. It is that accurate!, I can also shut the Diesel pump down remotely, probably the better benefit?. Mine WAS free, but they now charge an annual fee for new instalations. Might put one in the 13/60. But I suspect the "hidden switch" grounding the Coil, will be more apropriate to prevent theft in the first place. One (alleged) theoretical "advantage" is that 90% of stolen vehicles are parked up for 24hrs somehere remote to see if they do have a tracker, often allowing them to be recovered.
Pete