Trailer prep. Mudflaps on trailer tires (especially good ones behind the tire that has the sewer pipes behind it), and wrap the pipes (water, sewer LP gas) in pipe insulation and wrap that with electrical tape to keep rocks from putting holes in them. The rocks will even hole the copper tube for appliance LP gas if they are exposed under the trailer (mine were), The front of the trailer can get the rhino lining type stuff shot on it to protect it, I used truck mudflaps screwed to the front of the trailer where rocks would hit it from my truck tires. I saw one truck that used a skirt of some type of cloth hung from the bumper of the truck to the front of the trailer to stop the rocks, it was the best way to do it. I also found that the back of the truck was getting hit by rocks that bounced off of the trailer, the cloth skirt would have stopped that. If you carry bicycles on the back of the trailer, be ready to see the filthiest bikes you have ever imagined, we carried the bikes on the nose of the truck in a box reciever mount, used a front hitch to hold it. Others used covers on the bikes to keep off the dirt. If your batteries are older, get new ones, the vibration will get an older battery quick. We had 3 batteries, the oldest one failed 2 weeks in, shorted cell. All terrain tires look cooler, but the smoother treaded highway tires seem to throw fewer rocks. Running boards on the truck will stop rocks from chewing up the sides of the trucks, saw a lot of dually trucks with the front of the rear fender chewed to pieces!