Here is the recipe for the car-mix that I like. It is simple, healthful, and won't go stale on you for quite a while so you can leave it in your glove box and forget about it for a week or two.
Long-Lasting Car Snack Mix1 cup nuts
1 cup dried fruit (I like a mix of dried berries)
2 cups unsweetened cereal
Makes 8 1/2-cup servings
Protein: 4 g
Fiber: 5 g