Hi, Hussein and happy Eid Ul-Adha,
It is great to see you and your enlightening threads here. If you allow me, this is just my take on this issue. I think it depends on what you mean by 'garage'. If you mean a place to park your car, then using 'in front of' seems natural. However, if you mean a place where you buy petrol or where you can fix your car, then 'opposite' is the better one.
BTW, the following thread is closely related to this topic: