A car wash, or auto wash, is a facility used to clean the exterior, and in some cases the interior, of cars. Car washes can be self-service, full-service (with attendants who wash the vehicle), or fully automated (possibly connected to a filling station). A car wash, or auto wash, is a facility used to clean the exterior, and in some cases the interior, of cars. Car washes can be self-service, full-service (with attendants who wash the vehicle), or fully automated (possibly connected to a filling station).