Cars should come equipped with the vehicular equivalent of a PLB. Something like OnStar, but not totally reliant on cellular service (It should be something that can take advantage of both cell lines and communication satellites).

That way, if something ever happens while you're in or near your vehicle, you can hopefully get help notified and aware of your location. That way, instead of having to survive for a few days, you might only have to make it for a few hours. I truly think it would end up saving a lot of lives.

I know many people venture outside their homes under the impression that help is just a cell phone call away. Fact is, cell service is often sketchy at best, especially once you get away from suburban areas. Unless you're prepared with some other form of communication it can be quite a while before help comes, if it ever does.