Work on the new racer commenced in late 1952, and by spring 1953 the mid-engined type 550 was ready to go racing. It was a simple design: ladder frame with six cross members made of welded tubes topped with a hand-built aluminum body which fitted like a glove. The shape was very purposeful after extensive testing for maximum aerodynamics and minimum drag. The Volkswagen-based Super 1500 opposed four-cylinder engine was mounted between the axle and the driver, giving the design nearly 50/50 front/rear weight distribution with a driver aboard. Each car built utilised parts from both the 356 and the VW Beetle including suspension and the dynamics of the body and chassis evolved on every build until the release of the RS550/1500 spyder. Porsche believed they had finally perfected a race car that would put them on the map of motor racing and be used as a viable product to sell commercially.