The GM Aero-X is a concept car that was made in 1981.

One of the more notable features of the Aero-X was the absence of exterior moldings and the use of flush glass all around the car. This study in aerodynamics represented the latest example of a fuel-efficient car, designed without sacrificing aesthetics or comfort.

The hood sloped down in a steady curve and used a unique cooling air inlet under the nose. The wheel covers were flush with the wheels, which were mounted in line with the body sides to give the car a "slippery" configuration.

The rear of the body was specifically shaped to let air flow smoothly over it. The car underbody from the air inlet rearward to the axle was carefully shaped. A pair of progressive widening wedge forms began under the nose and reached their maximum width at the front of each wheel opening. This insured that the air which was not used for engine cooling was deflected efficiently under the fiberglass car.

Aerodynamic tests showed that the wheelhouse space usually required for wheel movements in bumps and turns contributed to overall drag coefficient. In the Aero-X, each wheel opening incorporated a unique flexible spacer which smoothed the airflow along the entire body side and permitted all the required wheel motions.