hatchbacks and rear end collisions

[JohnM]

There might be a reason why hatchback versions of practically the same chassis are more expensive e.g. Yaris/Vios, Jazz/City, etc. You get a shorter car for the money but they might (I wish) have reinforced the rear enough to survive anything a sedan can take. Does anyone have weight comparisons between sedan and hatch versions? If they have similar weights then all that additional metal might be in the back.