The limited-edition 1975 Cosworth Vega was a special performance version of the subcompact introduced long before cars like the Golf GTI or Mitsubishi Lancer Evolution. Only 2,062 were built. It was fitted with a fuel-injected DOHC 2.0L 16-valve version of the engine designed by Cosworth Engineering in England, which was famous for its racing engines. This engine was known internally at Cosworth as Project EA. Built by Chevrolet at its Tonawanda engine plant, the engine was fed by Bendix electronic fuel injection controlled by a computer in the glove box. 

The Cosworth Vega's exterior had special gold stripes and "COSWORTH TWIN CAM" lettering on the front fenders and rear cove panel. Interior changes included a gold engine-turned applique' on the instrument panel, a specific tachometer, and a plaque with the car's build sequence number. Also included were wide radial tires on gold-colored alloy wheels, anti-roll bars, and special exhaust with a dual-outlet tip. Air conditioning was not offered on the Cosworth Vega, due to interference between the induction system (specifically the air cleaner) and the air conditioner's evaporator case. At $5,916, it cost double a normal hatchback, and only $900 less than a Corvette.