I usually wash mine about twice a year. I use a car wash soap specially formulated for washing cars if it needs it to get rid of mud or dirt splashes on it, along with of course water. If it just has a coating of dust I just use water. I wipe it down when using the car wash soap with a washing mitt and dry it off with a genuine chamois. I wax it completely every 2 years with Meguiar's Gold Class wax. This works great for me. It was repainted in the original factory color around 20 years ago with a clear coat finish, and the paint still looks great.