Also i remember some post where someone mentioned about buying an old bmw after reaching canada.
My advise would be that since its only CAD4500, it has to be a really old model and the repairs on a brand like bmw will cost you a lot. Instead go in for something which is not that old and which is a cheaper brand. I guess when you first arrive, you want something cheap and reliable.
Go with honda or toyota. Cant go wrong. Also the mileage will be better thus saving you on monthly fule bills.
Just a suggestion.