Even though our MH came with the UltraGuard MudFlap, we had to re-mount several months ago as the original cheepo bolts/nuts broke/came loose. If a good samaritan hadn't told us it was hanging loose, it would have eventually broke free and most likely done serious damage to our toad.
1: Be sure and get the angle iron mounting bracket for bolting to the frame behinf the rear wheels. Our bracket had (2) holes and I drilled (2) additional holes for a total of (4).
2: Be sure that you use hard bolts, I believe they are Grade 8, and locknuts with locking washers are used. Here is a link on the UltraGuard you might check for additional info.
We will consider a Protecta-A-Tow in the future but the UltraGuard did a good job of keeping debris off the toad.