Under EU plans , cars sold from March 2018 will have a 'black box ' device . Gadget contains a phone-like SIM card which tracks drivers ' movements . Designed to help emergency services find vehicles in the event of crash . Comment: But officials fear it could be used by police to monitor motorists ' moves .
Under EU plans , cars sold from March 2018 will have a 'black box ' device . Gadget contains a phone-like SIM card which tracks drivers ' movements . Designed to help emergency services find vehicles in the event of crash . Government believes the device will add at least £100 to the cost of cars . But officials fear it could be used by police to monitor motorists ' moves .