One of the concept cars Ford displayed in 1981 at the Chicago Auto Show was the Mustang RSX. The initials stood for Rallye Sport Experimental. Ford's Ghia studio designed this two-seat sport coupe in Turin, Italy. With a wheelbase nearly 6-inches shorter than the production Mustang, the lighter RSX came powered by a 2.3-liter four-cylinder engine teamed with a four-speed manual gearbox. The body was finished in orange metallic, simulated all-glass doors, and a rear airfoil was used to improve directional stability and lessen wind resistance.
Source: Ford Mustang RSX Concept by Ghia 1980 | GTPlanet. https://www.gtplanet.net/forum/threads/ford-mustang-rsx-concept-by-ghia-1980.332678/
Images: Ford; World Cars 1980