The M7A was an open-wheeled single-seater with a mid-mounted engine driving the rear wheels. The chassis was a bathtub-type (i.e. open-topped) monocoque made from 22-gauge aluminium alloy and 20-gauge magnesium alloy panels glued and riveted together and to three steel bulkheads. The monocoque terminated behind the driver's seat and the engine was used as a stressed part of the chassis, bolted directly to the rearmost bulkhead. The gearbox was then attached behind the engine, and the rear suspension – consisting of lateral top links, twin radius arms and reversed wishbones– attached to the gearbox and the rear bulkhead. The front suspension – upper and lower lateral links and radius arms – and the steering column were attached to the two bulkheads in front of the driver. Coilover springs and Koni dampers mounted outside of the body were employed front and rear.