Blast,
You raise a good question about stuff flying around in the car during an accident. Not to steal the thunder from what Frank2135 may post, but I can maybe shed a little light on this. I was in an accident almost two years ago, about 5am, driving a Ford Ranger with a cap on it. I was hit by a F-150 that ran the light, hit the passenger side of the bed of the truck and spun me around 2 1/2 times. I came to a stop facing the opposite direction of where I was going.

Now to the stuff flying around the vehicle. In the cab, I was now wearing my ice tea that had been in the cup holder. My cell phone and a number of papers had been thrown throughout the cab. Some items that used to be under the seat were no longer.

In the back I had two Rubber Maid type bins (about $4 each) tied in with bungee cords. One bin with papers, business cards etc., and one with vehicle needs - oil, anti-freeze, and other fluids. I also had a "Justin Case" car safety kit with a number of extras and a PSK.

In short, EVERYTHING WAS EVERYWHERE - outside of the truck. The cab was laying to the side of the road. The bins were of course destroyed and even the Justin Case kit had been ruined.
nearly 500 business cards and all sorts of paper work decorated the highway and anti-freeze that had been bottled was now flowing over the pavement. Truck was totaled. Some bruises, a little blood, lots of broken glass, no airbag deployment. Walked away from it - that makes it a good day.

Quick note to self - buy better bins and don't get hit.

Hope this may educate someone in at least a small way - it did me.
Tom