The compact-sized Granite crossover concept shown by GMC at the Detroit Auto Show proved extremely popular with attendees, and the "Professional Grade" division at GM really wants to put it in production. According to new GMC product marketing director, Lisa Hutchinson, the main stumbling block right now is figuring out how to build the doors. The Granite featured the same rear hinged back doors that are commonly used on concepts to show off the interior.
The goal is to retain the door design for production to maximize access to the rear seat. However, the doors will have to be engineered so that the car can pass side impact safety requirements, an extremely difficult task without a fixed B-pillar, especially on such a small vehicle. The engineering feat has been managed before, as seen on the Mazda RX-8 and Honda Element, but the rear doors on the concept Granite would appear to require a larger opening than the demi-doors on either of the two Japanese offerings, making engineering significantly tougher. Of course, GM could still build the model with a hidden pillar à la Opel's 2011 Meriva, but that might compromise some of its appeal, or its utility if they can manage to build it with the concept's trick folding seats. In any case, GMC itself has shown that it can build rear-hinged doors, as it already has the Sierra extended-cab pickup, but that vehicle's body-on-frame architecture and less weight-sensitive construction could make that an easier manufacturing feat.
At this point, the fate of the Granite remains up in the air.