Indeed an emergency SMS should eventually get through and should keep trying until its does.

If you have a smart phone, consider using an app such as the Ordnance survey 'OS Locate' which allows you share your location with contacts. I think Strava (premium) also offers such functionality.

However, IMHO there is no real substitute for telling people where you are going, an approximate route and ETA and then letting them know when you return.


Not sure on the dashboard note idea - who would know where to look and would that not just be an invite for somebody to break into your car?