I got a hidden room behind a refrigerator in my garage that no longer works. so i just push it out and there's my growroom. There's some light leaks so i set the light timer so it's off when my parents get home and thankfully they work a lot. got a carbon filter in there and everything and it's almost silent.
In your garage? Wouldn't it be your parents garage? Since your growing in their house, without their permission?
I hope you live in a legal state and you aren't putting your parents at risk. It is one thing to grow legally w/o them knowing, but putting them at risk would be pretty uncool.