Had Ford done a full recall for its infamous "park-to-reverse" automatic transmission defect, it would have been by far the biggest recall in history. A staggering 21 million vehicles were built with a defect in the transmission that allowed a car that appeared to be in "park" to slip into reverse, says the Center for Autosafety, or CAS, a car safety organization in Washington D.C.

By the time the government officially recognized the defect in 1980, the National Highway Traffic Safety Administration had received more than 23,000 complaints and reports of 6,000 accidents and 1,710 injuries, with 98 attributed to the defect, the center said.

After initially threatening to force a recall, Department of Transportation, or DOT, officials reached a settlement with Ford, allowing it to avoid a recall in exchange for warning customers and sending out a warning sticker that could be placed prominently in the car's interiors.