Let's get this out of the way right up front: It's probably not what you think. A giant airbag does not shoot out of the dashboard and expand all the way across the cabin to pillow both front occupants like one of those big body pillows. A center-mounted airbag is one squiggly little kidney-bean-shaped thing that pops out of the driver's seat.
As of 2013, only three cars in the world will be equipped with these airbags: the Buick Enclave, GMC Acadia, and Chevrolet Traverse (all crossover-sized vehicles). It turned out that automotive industry supplier Takata was independently researching side-impact safety at the same time as General Motors. Rather than struggle alone, teams headed by Scott Thomas at GM and Richard Wiik at Takata joined forces. The center-mounted airbag that was born of this collaboration was 5 years in the making and resulted in nearly a half dozen patents.
Lest you picture a vehicle cabin filled with suffocating airbags, you should know that this airbag only comes out when it's needed and it doesn't stick around forever. And like every other safety system in your car, when it comes to an actual crash, your seatbelt is still number one for staying safe. Airbags can only help you if your body is not flying around the car.
So what good is this highly specialized airbag? Why spend so much time and energy on a weird-looking airbag that pops up between the seats? Three words: head-bonk prevention.