Good question Vince! as long as the car is not overly dirty I think you should be okay. If it is dirtier than normal you may think about actually doing a wash. But if it just gets some light dust on the paint I think you should be okay with detail spray and waterless wash. You always run the risk of scratches if the paint is dirty but with light dust or dirt and a soft towel the risk is lower. Just be careful when wiping not to apply too mush pressure!