Pfister is based on Porsche. The Pfister logo is in the shape of a shield, just like
Porsche's iconic logo. The name could possibly be a reference to "fisting", a sexual act. [Supposition - Consider revision.]
Pfister is probably owned by BF, similar to how Porsche is owned by Volkswagen.
In GTA San Andreas, pedestrians in areas like Paradiso and San Fierro can be heard saying what sounds like, "Have you driven a Pfister?" Sometimes, if the player is driving an expensive-looking vehicle, a pedestrian might comment positively, "Is that a Pfister?" This could mean that car brands were planned to be introduced before GTA IV.