If you hit hard enough, there is a safety feature LOL! The gas tank separates from the car and the fuel source is no longer a danger to YOU. It may be for wherever it lands!
FYI, a Vintage Spyder frame is very sturdy and the space frame around me protected me from getting dead. I did flop around wearing only the lap belt. I won't drive without the 5 points on me any more. Lesson learned.