The Seat Proto C was a concept car developed by Seat, shown following the earlier Proto T (also known as Proto TL). Like its predecessor, it was designed by Giugiaro's Ital Design studio, though this time it was explicitly credited to ideas from Seat's own Spanish engineers, again following the "Econosport" design philosophy. It was presented at the Mondial de l'Automobile in Paris as a compact four-seat coupe with two doors and an aerodynamic body. The side windows blended seamlessly into a large, curved front windscreen, with exterior mirrors that appeared to grow directly out of the body flanks; only the lower sections of the door and rear side windows could be lowered. In place of a conventional wiper, an adjustable scoop-like blade was fitted above the rear window.
Alongside the coupe, Seat proposed several alternative body concepts, shown only as design sketches: a cabriolet with covered rear seats, a speedster with an empty windscreen frame acting as rollover protection and a periscope-like central link to the rear deck, and a four-seat "Free Time" version with similar rollover protection, a low racing screen and a rear wing.
Proposed engines ranged from a 1-liter four-cylinder producing 60 hp up to a multi-valve six-cylinder unit rated at 200 hp, with a G-lader supercharged Volkswagen powertrain among the options, and four-wheel drive was also mentioned as a possibility alongside front-wheel drive. Planned technology included electronically controlled suspension, automatic traffic information, electronic parking distance measurement, pollen-filtering cabin air, a solar roof intended to maintain interior and engine temperature overnight, a collision protection system retracting the steering column while tensioning seatbelts, and an automatic engine stop-start system below 5 km/h claimed to cut fuel consumption by 15 to 20 percent. The car measured 3910 mm long, 1670 mm wide and 1120 mm high, with a 2440 mm wheelbase and track widths of 1570/1435 mm. Further development by Seat's engineers was anticipated.
