Survival gear?

[buddha]

I'm posting this in the auto section because, although it's not strictly an automotive item, a survival kit is something I carry in my car. That's something that could be pressed into service in the event that I got stranded on the road up here particularly in winter.
The plan, were I to get snowbound in the car, would be to stay with the car and try to summon help by calling or texting with the cell phone. A lot of people think that when the car goes into the ditch that it's time to start walking. I don't agree with that. In my case I have a 30 mile commute over 2 lane county and state roads to go to my night shift job. I can sometimes do the entire 30 mile trip seeing only one or two other cars the whole way. So help doesn't always come along when needed.
The obvious things I keep in the car are snack foods like protein bars or Clif bars, a couple of bottles of water, and a sleeping bag.
I also keep 2 cans of Sterno. In the event that I would get stranded and can't get the engine to run for whatever reason these can provide heat for short term warmth inside the car.
Does anyone else keep a kit like this in the car? What kinds of items do you keep in yours to sustain you if something goes wrong? I'm interested in ideas for mine but also a discussion of strategy/planning in the event that something does go wrong. 

[Slyfive]

sure do, I have a comprehensive first aid kit, lighter/matches, compass, knife, waterproof paper and pencil, a space blanket, rain poncho, gel hand warmer, wire for holding up a loose muffler etc, a socket set, an adjustable wrench, and a solar charged torch that I leave on the dash during the day.