I have a two bay shop and each bay is 20' wide by 40' deep with 14' ceiling height. It has 18" thick concrete floors, so I could use a 2 or 4 post lift. At the moment I don't have either one, but when I buy one it will be a 4 post. I have more than one project to do and I will opt for the rolling jack tray and other accessories to do servicing. I am too old to be rolling around on the floor positioning lift arms.