Our mud flaps are very durable and can hold up to the harshest conditions. Like your vehicle, they will require cleaning. We recommend car wash soap, water and a little elbow grease, or a pressure washer, will do the trick 99% of the time. If you find that your mud flaps have something on them that will not go away easily, some of our customers have used citrus based degreasers that do not have harsh chemicals in them.