I'm sure there are plenty of people that would chime in about Buicks being safe in a head on or other types of collisions. I myself haven't been in a head on collision, but I did have accident with the side of another vehicle at that speed (35 mph) in my GN... IMHO I'm so glad that I had my GN instead of a smaller car... I was still able to drive the car home from the nationals in Ohio. The accident itself, I recieved NO injuries. It felt like I bounced off. I imediately jumped out of my car to make sure the people in the other car were OK, but I had ZERO problems. That would have just been an expensive airbag going off for an unnecessary reason. Plus airbags only go off in FRONT collisions, not side impacts unless you have one of these newer cars that SURROUNDS you in airbags.
I'm not AGAINST airbags. But they do have their side affects as well. Including, abrasions to the face, possibility of a broken nose, 2nd and 3rd degree burns to the fingers and hands as well as temporary or possibility of permanant hearing loss. I remember WAY back in the day when I was first learning of how these things work... it's essentially a bomb in front of you, controlled by a bag. When it goes off, it's basically gunpowder pellets or similar detonating product that inflates the bag rapidly. The exploded gases are vented out ports behind the steering wheel. Since your hands are on the steering wheel, they may get burned from the escaping gas.
Also, I don't think there are any aftermarket companies doing this for many reasons. Probably including liability and engineering. The engineers at these auto companies have to figure the exact inertia values for that bag to go off as well as what size the bag is per the distance to the windshield and occupant, and millions of other factors.
In short... interesting idea, but REALLY a far cry to reality.
Plus you don't want something like what used to happen in the early airbags. Now airbags only go off if above 12mph, but back in the days, you could literally KICK the front bumper of a car that was parked and it would go off.