A new mini-sized Ford Motor Company concept car is so versatile it can be converted into four different vehicles -- from a two-seat sports coupe to a four-seat station wagon.

The Prima -- the result of a collaboration between Ford's Design Center in Dearborn, Mich. , and Ford Ghia Operations in Turin, Italy -- was shown publicly for the first time last month in California and will be on display at the Society of Automotive Engineers' Automotive Engineering Congress and Exposition in Detroit's Cobo Hall February 23-27.

In its basic form, the Prima is a two-seat pickup truck. By adding three different removable tops, the Prima is quickly converted into a two-seat sports coupe, a 2+2 three-door fastback, or a four-seat station wagon.

"While this essentially is an idea car, " says Gene Bordinat, Ford vice president - Design, "it incorporates technical and design features that make it a highly practical approach to meeting current market demands for an economical, utilitarian vehicle.

The Prima has only a 90-inch wheelbase -- 4 1/2 inches shorter than a 1976 Pinto 3-door -- but has a transverse-mounted engine and front-wheel drive which eliminates the drive-shaft tunnel and makes possible the wide range of body styles we have been able to provide within the same basic vehicle. "

The different steel tops are clamped into place using simple latches similar to those used to fasten a convertible top to the windshield. The fastback top includes a hatchback or third door in the rear. The rear of the wagon top lifts, while the bottom can be lowered to provide easy loading and unloading.

The Prima features an all-steel body painted red and forged-aluminum wheels painted white. At 157 inches in overall length, it is a foot shorter than the 1976 Pinto but almost 2 1/2 inches higher at 53 inches. Overall width is 61 inches.

The Prima excels in its aerodynamic properties. Because of its exceptionally clean lines, the rake of the front windshield and low frontal area, the Prima is designed for outstanding fuel economy.

Recessed, rectangular headlights highlight the front of the car. Three horizontal chrome moldings extending around the front fender corners to the wheel cutaways conceal slots that direct cooling air to the engine compartment. Similar chrome strips accentuate the rear of the vehicle.

The interior features tan contoured leather bucket seats. The rear seat pulls down to form part of the bed floor in the pickup and to provide additional carrying capacity in the fastback and wagon versions.

Powering the Prima is Ford of Britain's Kent 1100-cc four-cylinder engine, mated to a four-speed manual transmission. The spare wheel and tire is mounted in the engine compartment to provide additional utility space in the car's rear.