As an adjunct question to my urban/suburban choices post, I was thinking about how to survive a specific weather/climate scenario.

You get stuck in your vehicle due to a winter storm. You are either too far from or unable to trek to safety. Because the snow is over the tailpipe, you can't run the car for heat. What are the best things to have with you? Here are my thoughts. What am I missing?

Extra socks
Hat/balaclava
Gloves
Cold weather sleeping bag
Candles (and matches)
High calorie energy food
Water

As far as additional heat sources, would something like sterno give off enough heat without giving off toxic fumes?