Tale of two cars (Physics question)

Billiard balls tend to have elastic collisions, so neither is very “detrimental”. Unless you ramp the velocities up to 11, in which case the collisions stop being elastic. “Detriment” seems to require inelasticity.

It seems to me you’re overparsing the word “detrimental”. If you want to get into that level of detail, you’re going to have to specify which make and model of car, and what angle they intersect, the orientation and position of each car, whether one car is empty and the other is loaded with exercise weights, etc, ad nauseum. There was nothing in the OP to suggest he wanted a run down of how much each car collapsed, or if the trunk was sturdier than the hood, or if the windshield cracked or not, etc. He asked a very generic question with limited constraints, suggesting that he was looking for the textbook situation.

Exactly, thank you for coming up with this phrasing.