I've only installed one so far. I'll install (attach) the rest later when I have time to wipe the rust off with alcohol wipes. It says no, but I think it's a good idea. There were NO instructions included. However, it is not difficult to guess. I will post another photo when everyone is done. Even after driving it through the car wash. THIS will be a real test. I like the look of chrome. If you look like this, they're worth the money (as long as they don't fall off).