garage insulation

thanks for the input, yeah no ceiling, basically just a frame and shell. I can do that radiant barrier for a few hundred bucks, I know you get what you pay for im just curious if anyone has done this and if it works like im thinking it should. im gonna call a spray foam company soon and see about a quote but like I said, curious if this will work or if anybody has insulated their garage if they have one built like this.