My garage must have been made at the same time as yours, it's also 2 car garage with the laquered chipboard walls, but mine is an open truss style, maybe I could add plywood in there to make it an attic, but something to think about for the future. Someone notched out every single joist to fit the garage door rails in which is a big no-no and its really shakey so need to fix that first. I want to add paneling to the walls instead to make a better appearance.