Larry Copeland of USA Today wrote an interesting article about a "Yellow Dot" car program that is defined in the article as:
The Yellow Dot program is designed to help crash victims, especially seniors, communicate with rescuers during the crucial "golden hour," the first 60 minutes after a serious crash that can make the difference between life and death for the critically injured.
The yellow dot would go on the back window of your primary vehicle and indicate to EMS and other emergency responders to look for the yellow folder in your glove box that would contain "a photograph, medical conditions, prescriptions and other vital information."
This may be an antiquated system given the technological advances we have but sometimes the acronym KISS (Keep It Simple Stupid) comes into play. Not everyone will purchase the brand new car that sends an alert to the nearest EMS center, where each responder has an iPhone or "App" that automatically uploads your health information.
Any system that better helps you in a time of need where you may not be able to properly communicate is something worth investing or looking into.