That is true, H.B. Halicki who owned a large salvage operation, wrote, produced, directed, and starred in the film, providing most if not all of the cars from his own business. He also did all of his own stunt driving in the movie, and suffered a serious back injury. Some of the crashes were not in the script, but were kept in the final version of the film. He died several years later, while filming another movie when a stunt went wrong. That yellow 73 Mustang was built from the ground up, by him, and was the only one used for all of the stunt work. There were a couple of identical ones that appeared in the "glamor" shots. Amazingly, the stunt car survives today, and still runs.