Starting in the late 1970s, Ford and Ghia started exploring a series of futuristic designs under the "probe" series of concept cars. The Probe I, first shown in 1979, was a wedge-shaped design that incorporated a number of drag-reducing features like covered rear wheels and pop-up headlights. This was followed the next year by a much more conventional looking Probe II, whose hatchback styling is reminiscent of the Pony cars. 1981's Probe III was an advanced demonstrator with covered wheels, but its bodywork evolved into the more conventional Ford Sierra (or Merkur XR4Ti) and styling notes were used on the Ford Taurus. 1982's Probe IV was a more radical concept car with an extremely low Cd, and evolved into 1984's equally radical Probe V.
In the 1980s, a predicted increase in oil prices prompted Ford to give the Ford Mustang a major redesign. The new design would be based on a totally new platform introduced to Ford by Japanese car manufacturer and Ford partner Mazda. But when the new generation of the Ford Mustang neared its release date, oil prices dropped to an all time low and Ford Mustang buyers expressed their displeasure in the style of the proposed replacement. The car was eventually released, not as a Ford Mustang but as the Ford Probe.