I did this repair about 2 weeks ago and its holding up great with no signs of damage. What you will need is - sewing needle and black upholstery thread, small drill bit a little wider than needle,drill and Permatex Black Rubber Sealant. How I did this- First remove and clean off mud flap with soap and water. Next- drill holes in mudflap about 3/4" above and below tear. You can space them out however much you feel you will need to hold mud flap together properly. Next use the needle and thread to bring together tear in mud flap passing through the holes you drilled around 8 are more times then tie off and cut end of thread. Next use the Permatex black rubber sealant on both sides of tear trying to fill in the tear itself, then use a ample amount on and around tear. Also cover the thread and the ends of thread you tied off with rubber sealant. Let dry completely and you're good to go.