they both denote the action was completed. That is what strook me as weird but I guess other than the rigid rules I know about imperfective and perfective.
Note that the Russian imperfective can denote multiple actions in the past, like:

As a child, I used to catch crayfish in the creeks.
В детстве, я ловил раков в ручьях. (not поймал)

The question "когда ты машину разбивал" sounds like he is supposed to crash the car many times. In certain contexts, this sentence would sound ok to me.
I guess it's all about the pure meaning of a phrase rather than about this or that verb used. Replace "Машину" with "Лагерь" (camp) or "Палатку" (tent) and the verb "Разбивал" gets another meaning "pitch" and now the sentence "А когда ты лагерь разбивал?" doesn't sound weird at all nonwithstanding the fact that the overall structure and the verb are the same.