Airbags only works when the seatbelt is worn...
Is that true ? Surely not.
In the US, airbags are designed to offer (some) protection based on the people NOT wearing seatbelts as alot of americans still don't wear / trust seatbelts. In europe where the vast majority of people DO wear seatbelts, the airbags are designed to work on the basis of the people wearing seatbelts.
The difference is the time it stays inflated and size mostly.
I don't know why its so hard to believe that 60 mph did that to a car. Although they feel very solid, like I say in reality its only a couple of mm of steel mostly to protect you.
Doesn't matter how much you pay for the car either, have a look at the picture gallery here for what happened to an RS4 recently. I would guess 30/40 zone at that point but no idea how fast she was going, observe how the lamp post split the car in half lengthways...
http://www.eveningexpress.co.uk/Article.aspx/1392731