Chris has a good point.
And if you really want to do it completely - no holds barred, here's a suggestion....
Measure where you want to put the TRS and where the bolts will be. Then check underneath to make sure that the bolt holes will be equidistant from the corners of the floor to maximize strain strength. Then, use a digital caliper to measure the outside diameter of the bolts. Find a drill bit that is exactly .000001" smaller. Make a template out of plexiglass so that you can see through the template and make sure you stay where you're supposed to be. Drill the holes. Now, treat the inside of the drilled holes with zinc phosphate, and then seal with epoxy. Lightly coat the bolts with anti-seize. Now mount the TRS having somebody under the trailer to help torque the bolts to spec. Before doing anything else, now go ahead and load a bike into the TRS. Get Emerson to sit on the bike, and lean his head forward, reverse, and then side to side - then dismount. Now retorque the bolts to spec now that they've been stressed. Wipe the bolts down, then paint them with Ospho. Now, built a small aluminum box to fit under the bolts. Use flexible gasket material to go between the floor and bolts and the box, and then mount the box to secure it and seal the assembly. Then use some silicone to seal the seams.
If you've read all of this you have way too much friggin time on your hands and I don't want you near my trailer.