I usually don't eat a lot of 'just add water' packaged foods, but I will pick up a couple at the store today. I can donate them every 6-8 months then.
Now I have to go at my ramen noodles for lunch!
Just buy some tuna packages or canned tuna, and keep it in the car, and a can or two of pork and beans, every two years replace it, and take the old ones back to your pantry, they will be fine, even in desert heat.
Things do keep a little cooler in the trunk, especially if kept wrapped up in your gear.