With a vehicle wieght and space is not a consideration vs a bugoutbag. However, freshness is, especially in a vehicle subject to wide temperature extremes. You mention a hot meal as a morale factor. A MRE with heater pack would be the optimum solution. Using a stove in your car risks toxicity depending on the fuel. Opening a window to vent loses valuable warm air. A thermos with a hot beverage and a small selection of cold foods; candy, trailmix,driedfruit, powerbars etc. make for variety and are easily rotated.