Abstract: A conventional sedan is converted to a car with a lengthened engine compartment and a body which is correspondingly shortened immediately behind the door posts. Longitudinal sections of the frame below the car body behind the door posts are removed and welded into the frame at the engine compartment. Corresponding sections are removed from the roof, floor and drive shaft tunnel immediately behind the door posts to divide the car body into front and rear sections, after which these sections are welded back together to provide the converted shortened body. Structural reinforcements are added for the lengthened frame at the engine compartment. Also, longitudinal upper girders are welded to the firewall for reinforcing the lengthened hood for the engine compartment. The radiator is displaced forward from the engine, and an air tunnel is inserted between the radiator and the fan at the front end of the engine.