I think the question that you should be asking is:
So, what result would come to a humanin an old steel car interacting with a new age econo car, say at about a 60-100mph collision
Newer cars are designed to take the impact instead of the driver/passenger....older cars the driver/passenger took the impact. If I was to pick which car to be in the accident as a driver, I would most definately pick the newer econo car. Most newer cars have front/side/passenger airbags. You take a hit in one of them, its like being surrounded by bubble-wrap. You take a hit in an older car, you bounce around like a popcorn kernel in the microwave.
And btw...the newer 'econo' cars, they are made of steel also...its a different type of steel, its called High-Strength Steel.
Don't get me wrong, I would MUCH rather be cruising around in a '56 Chevy then a newer Nissan...but for a family car...something that my wife and kids would be passengers in...give me the throw away cars of today.
Later,
WEIMER