Thereâ€™s no missing a GP30â€™s characteristic â€œhump,â€ which was developed at the GM Automotive Styling Center. As well as creating a more modern appearance, the design was a practical way to house air intakes for the central air system and dynamic brakes. Bachmann carries on the prototypeâ€™s innovative history by offering a new DCC sound-equipped model. Our exclusive Sound Value SoundTraxxÂ® diesel sound package includes prototypical prime mover, 3 air horns, and bellâ€”all in polyphonic 16-bit sound. This model also features all-wheel drive, operating headlight, and E-Z MateÂ® Mark II couplers.