Visitors at the Detroit Auto Show reportedly flocked to GMC's display of its compact-sized Granite crossover concept. It was so popular that the "Professional Grade" division at GM wants to put it into production. Lisa Hutchinson, the new GMC product marketing director, said that the primary obstacle is coming up with the solution on how to build the doors.
The Granite had the same rear hinged back doors that are used on concepts to showcase the interior.
GMC would have to keep the door design for production to optimize access to the rear seat. The doors have to be engineered so that the car can meet side impact safety requirements.
This is a very difficult task without a fixed B-pillar, but it becomes more challenging because this is a very small vehicle. The designs on the Mazda RX-8 and Honda Element prove that this engineering feat has been done before but the rear doors on the concept Granite would need a larger opening than the demi-doors, making engineering considerably more complex.
GM can opt to build the model with a hidden pillar a la Opel's 2011 Meriva, but this might lessen its appeal, or its utility if it is built with the concept's trick folding seats.
GMC has actually proven that it can build rear-hinged doors, as it already has the Sierra extended-cab pickup. Nonetheless, that vehicle's body-on-frame architecture and less weight-sensitive construction mean that it's an easier manufacturing feat.