The B05/40 can be seen as an evolution of the MG-Lola EX257 (also known as Lola B01/60), in that many mechanical and aerodynamic elements are shared between the two cars. While the front fenders appear similar in shape, there are major dimensional differences between the two cars (1000 mm over hang vs. 810 mm) such that the B05/40's fenders are bespoke to the car. The nose is raised in a fashion similar to the EX257 while lacking the opening grill at the tip. This opening is instead replaced by two large NACA ducts placed on either side of the nose. Behind the cockpit, now mandated twin rollover hoops replace the single roll hoop which originally sat behind just the driver. The air intake for the engine is placed in a nacelle between these rollover hoops, while turbocharged cars use a large duct placed to the left side of the cockpit.