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.