of Product Planning and Research. A proponent of downsizing, Sperlich conceived of a "World Car" that could be sold in both Europe and North America as a solution to the needs of the various divisions. At the time, the Ford small-car product line included the subcompact Pinto and the Mustang II and the compact Maverick; while the Mustang II was several months from release, the Maverick was derived from the Falcon. Lincoln-Mercury sold no small cars of its own, importing the Capri from Ford of Europe. Ford of Europe sold the Escort as its smallest car; Ford UK sold the Cortina while Ford of Germany sold the Taunus Fox platform development In December 1973, Lee Iacocca formally approved development of the Fox platform. Sharing its name with the Audi Fox (although not named after it), Ford executives experienced with the automotive industry outside the United States sought to benchmark a new design from a popular European subcompact design. Development started in early 1973 on both a short-wheelbase version to replace the Pinto/Cortina/Taunus lines and a long-wheelbase version that would become the Fairmont. Although the Fairmont would be the first Fox-based car to reach the market, development was guided by an anticipated sport coupe to be based on the new platform. By 1974 the difficulties faced in meeting the conflicting regulatory requirements in different markets and differing production methods used by the various divisions had killed the world-car idea. While unable to replace the Cortina/Taunus, the Fox platform remained a multiple-wheelbase design, as the short-wheelbase version remained in development to replace the Mustang II. In 1975 North American Automobile Operations took over development of the Fox platform from Sperlich's Product Planning and Research group. The first running Fox (Fairmont) prototype was a Cortina with a modified suspension, using MacPherson struts and torsion bars. The torsion bars would not appear in the final version. Chassis overview The Fox platform, like most compact and mid-size cars of the late 1970s, was designed with a rear-wheel drive layout. In contrast to the full-size Fords and Mercurys of the time, the Fox platform used unibody construction. The Fox platform used MacPherson strut front suspension, continuing the use of a live rear axle suspension configuration. Initially configured with rear drum brakes, four-wheel disc brakes were added to higher-performance vehicles, including the Continental Mark VII, Ford Mustang SVO, 1994–2004 Ford Mustang, and the Ford Thunderbird Turbo Coupe.