 The design brief for the exterior restricted the use of aerodynamic aids , and aimed for a stylish yet functional body similar to the Jaguar D @-@ Type . Drag and lift were limited at the envisioned ground clearance for road use , but the design allowed for additional downforce when the car was set up for racing ; the body produced around 3 @,@ 000 lb ( 1 @,@ 400 kg ) of downforce at 200 mph ( 320 km / h ) . The design was also intended to have a variable rear wing that folded into the bodywork at lower speeds . Aerodynamic work was undertaken at the Motor Industry Research Association wind tunnel using a 1 : 4 scale model , as the project was unable to budget for a full @-@ scale mock @-@ up . 
