The blue 'A/C' badge under the Gauntlet name is based on the R/T performance marker. The circular front high-beam lights, reverse lights, and chrome side skirts are similar to the ones from the 1967–1968 Ford Mustang, while the C-pillar might have been taken from the 1969–1970 Mustang models.
The square tail lights seem to be inspired by the ones found on the 1970–1971 Ford Torino. The Gauntlet Classic is based on the first-generation Dodge Challenger, with the horizontally split grille based on the 1970 Dodge Charger, while the side profile is taken from the 1970–1972 Plymouth Barracuda. 6.2.1 GTA Online: The Diamond Casino Heist.