When using the foam nozzle of the car wash machine, ensure that the car wash fluid is sufficient and properly diluted to avoid nozzle blockage or damage. After use, the nozzle should be cleaned in a timely manner to remove residual car wash fluid and impurities, and to keep the nozzle unobstructed and clean. During storage and use, the nozzle should be protected from collision or compression to prevent deformation or damage.