The Plymouth X2S was a concept car shown as a fully drivable two-seat sports convertible, developed not in Japan but at the Mitsubishi Motor Corp. Cypress Design Studio in Cypress, California, one of the American West Coast design offices that Japanese manufacturers had by then established. It was first presented in Los Angeles, where Mitsubishi Motor Sales of America announced that elements of the X2S concept would appear in a forthcoming special sports car to be built by Diamond-Star Motors Corp. in Normal, Illinois, and sold through MMSA from spring 1989. Diamond-Star was the newly established, largely automated car plant built jointly by Chrysler and Mitsubishi.
That production plan led to the 1989 introduction of the Mitsubishi Galant-based coupe trio comprising the Plymouth Laser, Eagle Talon, and Mitsubishi Eclipse, though no convertible version of these cars was built at the time. Unlike the X2S, which used pop-up headlamps, early proposals for the front end had featured a Thunderbird-like nose with eight small square headlights; the tail, joined to a glazed fastback, also differed in its final production form from the concept.
Mechanically, the X2S was built on a shortened Mitsubishi Galant floorpan and used a Mitsubishi 2.0-liter four-cylinder engine with double overhead camshafts, 16 valves, and a turbocharger. Output was quoted at 200 hp in some sources and 203 PS in others, with figures of 199 horsepower at 5,500 rpm and 189 lb-ft (256 Nm) of torque at 5,000 rpm also cited, alongside a curb weight of 2,550 lbs (1,156 kg). Mitsubishi noted that the front-wheel-drive layout could readily be adapted to all-wheel drive, and that the engine was a derivative of the Galant unit also used in Mitsubishi Japan's HSR concept car. The car rode on 17-inch wheels with 45-series tires in some accounts, though production-style specification sheets list 16-inch cast aluminum wheels with P225/50VR16 Goodyear Eagle tires. Suspension consisted of a dual-insulated front and 3-link rear sports setup, with power-assisted quick-ratio steering and four-wheel disc brakes.
Performance was estimated at zero to 60 mph in about seven seconds and a top speed of around 140 mph (225 km/h). The two-door body featured an expected drag coefficient of 0.30. Inside, the leather-trimmed cockpit had an aircraft-inspired instrument panel with analog gauges, including tachometer, speedometer, and readouts for fuel level, coolant temperature, oil pressure, and turbo boost, along with high-back reclining bucket seats with lumbar support, an adjustable steering column, a leather-wrapped steering wheel and shift knob, and a stereo system with cassette or CD player feeding six speakers.