I'm planning to put together a winter prep kit for the car. What should I include to ensure that I'm as well prepared as I can be for whatever the weather and/or traffic may throw at me? I'm thinking drinks, snacks, something warm to wear, some kind of shovel, a torch. What have I forgotten? 
And where should I put it all? The glove compartment is tiny but could conceivably contain a torch and a few snacks but not much else.