Every once in while customers ask me about using a California Duster to keep their vehicles looking clean longer. Though I do not use one myself, I usually tell them they could use it only when the vehicle has a very light dust film (like the day after washing), but not to use it if their cars are any dirtier than that. Of course I tell them that it might lightly scratch their surface, but I'm trying to be practical for them. If they have a dark car, I shy them away from their use completely, but maybe I'm off base here?