And there were plenty of times when my dad was able to put those supplies to work.
Be it a maintenance issue or a snowstorm, keeping the following items in your vehicle can save you time and discomfort, and perhaps even your very life, should an emergency arise. Obviously, the necessity of some items depends on the environment in which you live/are driving through (you don't need an ice scraper in Tampa) and the season (though it's best just to stock this stuff and keep it stocked, rather than removing/adding things as the seasons change).
1. Paper maps. Sometimes — okay, plenty of times — Google Maps or Waze doesn't want to cooperate. And if you don't have service, their reliability is of no import anyway. It's always a good idea to keep paper maps handy of the areas you'll be driving through.
2. Snacks/MREs. You never know when you'll be stranded for long periods of times in your car. And depending on where you are, you could be dozens of miles from the closest source of help. Keep some MREs or granola/power bars in the back of your car to munch on while you wait for a tow truck to come, or to sustain you for a long walk to a gas station to call for help.