Nicely put: the crumple zone takes it all. There was a Fitth Gear episode once where they bought two used ford focuses (if I recall correctly), one was a patched-up former write-off that was acquired for substantially less money than the other one. A bargain, you would say. Then they did a head-on collision wit the 2 cars running into each other and trust me: you don't want to be in a patched-up car like that. The difference between the 2 cars in deformation of the passenger compartment was substantial, due to the cumple zone having taken a beating before. Unsafe.