From GM Heritage Center: The 1968 Chevrolet Corvette Astro-Vette concept car was an aerodynamic study to see how slippery the Corvette could be made. Two notable styling features were picked up in 1973 and 1974. In 1973, when most cars got huge, chrome, front bumpers; Corvettes got the Astro-Vette treatment. Then in 1974, the tail end was restyled, a la Astro-Vette.
The obvious features on the Astro-Vette were the extended nose, roadster windshield, closed rear wheel openings and extended tail. The nose was extended considerable and the grille opening was kept to a minimum. The long hood has no bulge, indicating that the car was a small block. Scribe lines on the front fenders were to be pressure actuated flaps that opened if under the hood pressure was too high. Designers took advantage of the B-pillar by crafting an airfoil to minimize air drag. Taking cues from the hot cars of the 30’s, the Astro-Vette had smooth wheel disks on very narrow tires, and rear fender skirts that were hinged at the top for tire access. Like the front, the back end was extended and tapered. Designers even added partial front and rear belly pans to smooth underside airflow. The interior was medium blue and stock, except for the racing steering wheel.