It is required in the EU. The mobile device only connects to the network in case of a crash. Of course, manufactures having to add a mobile device prefer to keep it connected continuously to use it for other things than required.
LTE-M/NB-IoT will solve this once it's activated on cell towers. Much lower consumption, it isn't paging the network at all times. They just have to shut it off when the ignition is off.
