Albany's Primo has always been GTA's honest full-size sedan, and it returns in GTA 6 through Trailer 1 and screenshots. The design nods to a late-80s Pontiac Bonneville. It has appeared in San Andreas, GTA IV and GTA V, where a Custom version joined it. Files list 1,800 kg and rear-wheel drive, both datamined. Expect it to be soft, unhurried and everywhere in traffic.
Rockstar has not detailed acquisition. The Primo is exactly the kind of car GTA fills its streets with, so expect to find one in traffic within minutes of starting the game. That is a pattern-based guess, not an announcement.
The community companion for Grand Theft Auto VI. Database, maps, guides and tools for Vice City and the state of Leonida.