Q. Can you take your car to a carwash (during the Nine Days) if it is very dirty?

A. Horav Shlomo Miller’s Shlit”a opinion is that there is no prohibition in washing a car during the Nine Days. (See similar opinion in Nitey Gavriel – Ben Hametzorim I p. 174)

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a