A few other items that should be part of a vehicle load-out would be 1-solar shower, no-rinse camping soap and other personal hygiene articles, 1-camping 5-gal. bucket toilet,T.P, waste bags, small bottle of no-rinse hand sanitizer and a small folding shovel.
All of this can be stored in the 5-gal. bucket so as to not take up much room at all, and ensure better health and morale.