谨慎挑选在车里吃的食品。

Given the above summary, write a detailed text in English for it.
Peanut butter, tuna and crackers are great staples. Have a box for food so it does not get smashed. Gallons of water are a necessity for a lot of things. The amount of food you can keep at any one time will be limited by the lack of refrigeration. Fast food is expensive when you're living off it. With old fashioned (large flake) rolled oats, powdered milk, bottled water, plastic cups, and chocolate protein powder, you can ensure that you always have a nutritious snack to fall back on.