As was pointed out at the beginning of this article, the center-mounted airbag was brand-new on only three vehicles in 2013, and GM wasn't ready to say yet which other models might be next to get it.
If it prevents head-bonking so well, why not just throw it into every car in the fleet, you ask? Good question! The answer is simple: It doesn't fit. Airbag packaging, with the bag itself and the little explosives that set it off and the electronics that tell it when to go, is pretty bulky. Yet, in regard to some of GM's crossover-sized vehicles, like the Enclave, Acadia and Traverse, Sharon Basel at GM said, "the size of seat allowed us to get it to market much quicker." Putting a big bag like this, packed with explosives, into a tiny commuter car would have been an engineering nightmare.
The other reason, Basel pointed out, was that crossovers are really popular family vehicles. They're more likely than some teensy commuter car to have occupants in both the passenger and driver seats. As much as everyone wants to keep you from squishing your spleen against the center console, we really want to prevent the driver and passenger from knocking each other out (or worse) with a solid head bonk after a side impact.
Since this technology is so new and in so few cars, it's neither regulated nor required by the U.S. federal government. Basel made it perfectly clear: "This is an industry first in terms of concept, development, design, engineering and getting it into the marketplace."
You may still be wondering -- even after all of this information -- if a glorified balloon in a weird shape will actually stop a "supersized" American from pitching into the passenger seat. It will indeed. Thomas, along with Richard Wiik at Takata, designed the airbag to "give appropriate coverage and restraint for larger occupants." As high school physics teaches us, a larger body will have more energy. And if the center-mounted airbag works for the big guys, it'll work for anybody.