<Li> A retractable artillery cannon on a turret </Li> <P> The new incarnation of the Tumbler was proposed by Nolan after he built a proof - of - concept model design out of Play - Doh - a model he admitted looked "very very crude, more like a croissant than a car". Nathan Crowley, one of the production designers for Batman Begins, then started the process of designing the Tumbler for the film by model bashing based on that shape . One of the parts that Crowley used to create the vehicle was the nose cone of a P - 38 Lightning model to serve as the chassis for the car's jet engine . Six models of the Tumbler were built to 1: 12 scale in the course of four months . Following the scale model creation, a crew of over 30 people, including Crowley and engineers Chris Culvert and Andy Smith, carved a full - size replica of the vehicle out of a large block of Styrofoam, which was a process that lasted two months . </P> <P> The Styrofoam model was used to create a steel "test frame", which had to stand up to several standards: have a speed of over 100 mph, go from 0 to 60 mph (97 km / h) in 5 seconds, possess a steering system to make sharp turns at city corners, and to withstand a self - propelled launch of up to 30 feet (9.1 m). On the first jump test, the Tumbler's front end collapsed and had to be completely rebuilt . The basic configuration of the newly designed vehicle included a 5.7 - liter Chevy V8 engine, a truck axle for the rear axle, front racing tires by Hoosier, rear 4 × 4 mud tires by Interco., and the suspension system of Baja racing trucks . The design and development process took nine months and cost several million dollars . </P> <P> With the design process completed, four street - ready cars were constructed . Each vehicle possessed 65 carbon fiber panels and cost $250,000 to build . Two of the four cars were specialized versions . One version was the flap version, which had hydraulics and flaps to detail the close - up shots where the vehicle propelled itself through the air . The other version was the jet version, in which an actual jet engine was mounted onto the vehicle, fueled by six propane tanks . Due to the poor visibility inside the vehicle by the driver, monitors were connected to cameras on the vehicle body . The professional drivers for the Tumblers practiced driving the vehicles for six months before they drove on the streets of Chicago for the film's scenes . </P>

What kind of car was used for the batmobile