Both answers are correct in grammer, it is depend on the speaker's position to use 进 or 出. I am in the garage and drive the car out, 出去。(away from the speaker's place and out) I am out of the garage and drive the car in , 进去。(away from the speaker's place and in) I think both conditions are possible, maybe somebody else drive the car in and I am not familiar, can't dirve it out. So it must have a initial condition.

I personally think it is a faulty question that has no right/wrong answer, something similar to the chicken and egg riddle. The question should provide an initial state, i.e. car is parked inside the garage or outside on the street. Whether the garage door is too narrow/small to drive through depends on the speaker’s personal and subject judgment on the reality and it does not always equal to the reality. For example, Judging the situation, I said to my father: “這停車位太小了我停不進去.” He asked me to get out of car and parked the car for me. Also, Normal garages I see have a normal door size. Otherwise you still call it a garage if it can't house a car? Whatever this question is testing, it is definitely not on the knowledge of Chinese.

If you can pass this kind of language test, you will be a chinese master! So anyway, keep on learning, you will find out which is correct someday!! By the way, Even I (A Chinese and live in Taiwan for more then 30 years) can not identify why answer is RIGHT?! Good luck and enjoy your Chinese learning!

There must be a different door you got in through. A big garage might have several doors.

if you want to go in to the garage the answer is 我开不进去 if you want to go out from the garage the answer si 我开不出去