Washers help spread the force of the bolt being tightened down. The wider the washer, the more area your screw is holding down. The metal clips help keep the mudflap on. Duh right? But I recent got stuck in the snow and I run the flapatax mudflaps on the front, rally armor basics in the rear. If it wasnt for the clips and washers i put on there, i might have done more damage to my car. If there wasn't any clips or washers who knos what would have happened. Get your clips and washers at Ace hardware. In case you dont know the sizes you need, the people who work there have a good idea. Food for thought.