About a month ago while backing up in the snow I cracked one of my mudflaps. I got a price from the dealership of $89.00. No way am I paying that much for a mudflap. Because the mudflap was hitting my exhaust and melting I had to do something. So to hold me over until I can find a cheaper one I did some simple rigging... after was all said and done the flap works great, and did not have any play.
1. First remove the mud flap.
2. Get 3/32nd's drill bit, a drill, some safety wire (I think I used 20 gauge) and a pair of needle nose pliars.
3. You will make a series of three holes on the mudflap from where the crack begins and ends. But before that drill a hole where the crack ends to prevent from further cracking.
4. Drill all the holes necessary.
5. Loop the safety wire through the three holes, start where the crack began and go to where it ends.
6. Once you have all the wires through all the holes, twist the safety wire with your fingers. Then tighten the wire with the needle nose pliars. You don't have to twist too tight or the wire will break.
7. Cut the excess wire and bend in the remaining wire to make less noticable.
8. Install the mudflap and you are good to go.
I realize this isn't the most detailed thread, but it is really easy. Here are some pics.