I remember 'back in the day' I would camp out in my 951 turbo. During one 24 hour team mtb race, I was sitting in the front seat of the car, front seat reclined, trying to get some sleep. The sun was coming up and it was morning. After riding all night, I was ready to relax.
All of a sudden, a large hissing sound came from the steering wheel airbag. There was a some smoke and a smell. It was very much like when Mel Gibson fired the bad 12 gauge shells in Road Warrior. Very much like lighting firecrackers only to find out they were ladyfingers. Nothing exploded in my face, it more "fizzled" out. I opened the doors to air the car out and tried to get back to sleep. The air bag was about 20+ years old at that point.
There was a moment of Confusion, WTF? Terror! and "Oh.. That's it?" I swear to this day the airbag crapped out on me, and thankful it didn't explode in my face, I went on about my life knowing it would fizzle no more, and I was no less safe than all the pre-80's cars I had driven until that point.
I do wonder about the airbags in my volvo. They are coming up on 20 years now, but the car has has been much better kept.