Would it be possible to make a car almost entirely out of soft materials to increase safety?

Imagine that vehicles were no longer made out of metal. Imagine they switched to newer materials that were very soft. I guess I am referring to materials such as foam and sponge and clay and other types of soft materials. Remember the car called The Adobe on the SNL skit in the 80's? Well as funny as that was, it was actually kind of a decent idea if you really think about it. Fatalities on the road would almost plummet down to zero if all vehicles were soft. Now, I know what everyone will say about this question. They'll say, "Well, what would you do if some of the vehicles on the road were soft and some were still made out of metal? The soft ones wouldn't stand a chance in an accident." Or they will say, "Those soft materials will never be durable enough." But just try to imagine if all cars were required by law to be made of soft materials and imagine the metal cars were outlawed from the road. And imagine if science really did find a way to make very durable soft materials. Couldn't this idea work then?