Have you ever watched a NASCAR race and seen one of those guys hit the wall going 200 mph? How in the world did they survive that? Well they had on a helmet, neck brace, and a 5 point harness. They are safer than airbags and a shoulder strap seat belt. Then why don't they put 5 point seat belt in daily drivers? They weigh less (better fuel economy, cheaper to make, and are safer than airbags. My guess is that people would complain about it not being convenient. Some might say that they are less comfortable or restrictive. I am not a big fan of air bags. Really they are only for people that don't wear their seat belt. Just look at the damage these things can do.
I'm curious is there any one out there that would trade the convenience of airbag and crappy shoulder strap for a 5 point racing seat belt.