So far, no one can tell which vehicles these brands have produced in the game.
In Grand Theft Auto: San Andreas for PC, there is a data file titled carcols.dat which names some vehicles brands: one known brand (Maibatsu), one later-known brand (Shitsu, not Shitzu) and two unknown brands (Nioka and Kunst).
They were very rarely encountered in GTA III Era games, however their use was greatly expanded in Grand Theft Auto IV, where every car has a designated brand. This is a list of vehicle brands that appear throughout the Grand Theft Auto series.
