The manufacturer's name may be a pun on Pussyfister, which refers to some one who shoves their entire fist into a vagina.[Supposition - Consider revision.]
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.