A friend of mine has a home made on-board air setup on a switch. He used a small electric air pump (like one found in roadside trunk kits for flats in a car) and connected it into a 10 gal. tank and managed to hide it pretty good in a Suzuki Samurai, so you could probably stuff a bigger setup under the bedsides somewhere, or in your toolbox. It works great for blasting air and filling up tires, if you go bigger can probably even run an air tool for minute. Just a crazy idea to use up your switch!