Cat 5 tracking systems

[dazzalse]

Our insurance broker has said that we need to install a cat 5 tracking system on our car otherwise the car will be uninsurable, they have suggested Navtrak ADR, having had this system before on another car and living in rural exmoor we were constantly getting calls saying they were unable to locate the car, can anybody recommend any other systems, the car already has a tracker but they have said this is no longer good enough