Ford and several third party companies offered many modified versions of the highly popular Mustang in order to cater to specific portions of the marketplace outside of the mainstream.
High performance enthusiasts seek more powerful, sharper handling, sports cars, while collectors and purists seek limited production and alternate or nostalgic styling, such as is commonly found on many commemmorative editions.
Still, others were made purely for experimental concepts such as the McLauren M81 (turbo) and SVO, which later influenced production model design. Most variants include both performance upgrades, and unique cosmetic treatments that are typically minimal to maintain the familiar appearance of a stock Mustang.
Although most of these Mustang variants were aimed at enthusiasts, a notable exception was the Special Service Package (or SSP), which was designed specifically for law enforcement.