Go ahead and read my post again, I get the whole thing on how cars are being designed to protect a safety cage from deforming and thus keeping the people from sustaining damage and what not and I understand how they have some areas that do crumple to absorb energy, I didn't need any of that explained. What I was asking was if two of the same five star cars crashing into each other would be as safe as one five star car crashing into a much larger car but an older one that crumples more. Again I'm not up with my physics but a combined speed of 80 miles per hour is the same as a 40 mile per hour crash into a stationary object? Are you sure? I would still think the forces would be greater when you're hitting another object with a large mass and large amount of energy moving towards you and designed to be very strong and not deform much.