The 1970 Citroën SM represents the pinnacle of French automotive engineering, a rare pre-production prototype built exclusively at the Ligier factory. This specific chassis, numbered 00SB0039, is distinguished by its unique 'Pré Série' status, featuring original pre-production door panels, a specific rear window, and a matching-numbers engine block that underscores its authenticity as one of the oldest surviving examples in the world. Under the hood lies the legendary 2.7-liter V6 engine, originally rated at 170 horsepower. While the listing notes a new engine installation with only 30,000 kilometers on it, the core components—including the original crankshaft and cylinder heads—remain intact, preserving the car's historic integrity. The power is delivered through a rare five-speed manual transmission, fully serviced to ensure smooth shifting. The chassis has undergone comprehensive mechanical attention, with rebuilt front and rear axles, an overhauled hydraulic system, and 100% new brakes, ensuring modern reliability without sacrificing classic character. Exterior-wise, the vehicle boasts a striking sand metallic paint finish that complements its pristine white condition. Inside, the cabin retains its original black leather upholstery paired with gray carpeting, alongside a pre-production dashboard and factory radio. Having undergone a full concours restoration in 2010 and suffering no accidents or corrosion, this SM stands as a unique piece of automotive history, combining avant-garde design with exceptional mechanical preservation.