Chassis No. WBAEC7209C8175000

This one-off BMW 6-Series began life as a standard 635 CSi before undergoing a comprehensive transformation at the hands of Mike Gibbs' MGA Developments Ltd. in Coventry. Established in 1979, MGA operated as a complete design-to-production service for mainstream automotive manufacturers, developing prototypes and other halo projects. Internally designated "Special Project M3," this BMW was conceived specifically as a calling card to demonstrate MGA's comprehensive capabilities, settling on the ambitious goal of creating the world's first fully retractable glass-roofed grand tourer. In 1982, the project moved forward with BMW Great Britain donating a factory-fresh 635 CSi and The Observer newspaper providing financial backing.

Through many preliminary sketches, its innovative glass roof system was engineered in collaboration with Triplex Safety Glass Company and Tudor sunroof mechanisms without the use of removable panels or soft tops. Instead, the design employed a sophisticated tracking mechanism that allowed separate glass panels and the rear window to retract into a specially designed compartment within a custom-fabricated trunk lid. To address solar heat gain, the glass incorporated silkscreen-printed patterns fused directly into the surface. The extensive modification process began with applying 200 kg of clay to the donor vehicle to perfect the body lines before creating templates for the new panels, all while maintaining sufficient structural rigidity through an integral roll-over bar.

Under the direction of former Porsche designer Stephen Ferrarda and electrical systems engineer Stanley Daniels, the MGA team completed the extensive transformation in a mere three and a half months. The exterior received an era-evoking two-tone grey finish with bespoke front and rear spoilers, side skirts, custom graphics, and Centra Type 6 alloy wheels that firmly place the design in the early 1980s. Mechanically, the car retained its original 3.5-liter M30 straight-six engine producing 215 horsepower and 229 lb-ft of torque, delivered through a precise five-speed manual transmission.

A contemporary article in Octane magazine verifies the project's construction cost exceeded £65,000-an extraordinary sum in 1982 that did not include the donor BMW! The prototype was completed on 27 September 1982 just days before making its public premiere at the British International Motor Show in Birmingham. While proposals included a potential limited production run of between 12 and 50 examples through BMW's dealer network, these ambitions never materialized-partially due to the mechanical complexities of the retractable roof system, leaving this prototype as the sole example.

Following an international press tour with BMW GB, The Observer Coupe remained with creator Mike Gibbs until 1993. In his ownership, approximately seven years after its completion, the complex retractable roof mechanism was converted to its current fixed glass configuration, addressing noise and reliability issues inherent in the prototype design. A meticulous history file documents its subsequent ownership history with MOT certificates and service records spanning from 1989-2023. In 2017, showing just over 18,000 miles, the BMW underwent comprehensive work spanning fabrication and paintwork, reported to exceed £26,000.

With just 19,280 miles indicated at the time of cataloging, this BMW represents a fascinating, nicely restored example of a 1980s prototype and an early exploration of glass roof technology now widely adopted in modern automotive design. While all 6-Series models offer an exceptional driving experience with their "shark nose" Paul Bracq-penned design and powerful inline-six engines, this particular example merits special attention for its comprehensive documentation, exceptional restoration, and cutting-edge, one-off design added to a rare low mileage manual.