Yep. Chassis spray, for salt: it's the only way. Later, a full detail will restore any damage done to the clear coat; wax and ceramic, etc. Afraid there is no other way. Leaving accumulated saline all over the bottom of the car is far more deadly than temporarily marred beauty. So far, I haven't seen a thing that looks like deteriorating or damaged clear coat. It's easier on a Silky Silver than it would be on a Deep Chroma Blue or Aurora Black or Panthera Metal, i.e. dark colors.