Modeled on the 2015 Dodge Charger, the Buffalo STX is the modern, meaner take on Bravado's family muscle sedan. It featured prominently in GTA 6's first trailer. Game files list 1,800 kg, rear-wheel drive, and an 8-speed gearbox, numbers that fit a heavy sedan with serious power. Expect big straight-line speed and a back end that needs managing in the wet.
How you get the STX has not been confirmed. Modern muscle of this sort usually sits at a dealership or in-game website in GTA terms, though street spawns are plausible for a Bravado. Treat this as informed guessing.
It was confirmed in Trailer 1.
The community companion for Grand Theft Auto VI. Database, maps, guides and tools for Vice City and the state of Leonida.