Take a first-generation Mustang, lift it on off-road suspension, and you get the Dominator Buggy '67, one of the stranger bonuses in the GTA 6 Ultimate Edition. Screenshots show a muscle car built for mud rather than the drag strip, and Rockstar's own description points it at the backwoods around Mount Kalaga. Think trail toy, not daily driver.
The Dominator Buggy '67 is included with the Ultimate Edition of GTA 6. Rockstar's description also mentions storing it at the Paradise Garage in Watson Bay, alongside a weapon locker and a spot to fence stolen goods. No other acquisition route has been announced.
So far it has only been shown in official screenshots.
The community companion for Grand Theft Auto VI. Database, maps, guides and tools for Vice City and the state of Leonida.