Back in the '70's gas crunch, a classmate at my Community College Auto Technology class had two different tricks to steal gasoline. #1 He worked at a Shell station and would put one or two dollars of gas in his car and then keep the pump on, then without clearing the pump, he would put the nozzle in the next customer's car and fill them up, having them pay the one or two dollars extra. I guess he did that until his tank was filled. #2 He installed an electric fuel pump near the gas tank filler pipe of his '71 Dodge Charger. He would park alongside another car, and pump gas from the other car into his car. Probably at night, but I'm not sure when he pulled #2 off. He was a nice guy otherwise, and helped me build my 1965 Valiant bracket racer during our auto class hours together, polishing valves, connecting rods, painting the inside of the cylinder block, etc.