Permanent fix for Coroplast underbelly

I have had mine out several times in the 4yrs we have owned it. I cut mine into 3 sections. In front of the axles, over the axles and behind the axles. I however have gone a different route than others with great success. Rather than installing a cross member of sorts to fasten it to, I laced it with wire ties. I drilled holes on each side of the cut about 2" from the edge, directly across from each other about 6" apart. I then zip tie the holes across the cut and just pull them snug. After they are all tight and cut, I run a bead of silicone the length of the cut and fill the holes.
This method has lasted up and down 95 many times!