I, too, wish I would have sealed my car. I thought that I might have too much loose flapping so went bare, right after a big Chicago snowstorm. Salt everywhere. I washed it when I got home but much of the aluminum developed white oxide and bare steel rusted quickly. Overall, I don't regret picking it up one bit as it was an adventure for my brother and I. But if I had it to do over I would wrap the body in 1 or 2 mil plastic and use vast quantities of duct tape to snug it to the body everywhere. About every 6 inches to a foot like a belt. Duct tape is cheap.
I also bought some one shot $10k cargo insurance from State Farm in case of an accident since truck insurance just covers liability with a trailer. I think it cost about $60 and I had a claim for my trunk handle which vibrated loose and fell out somewhere.
My trailer had a wooden bed and I scrounged some wood blocks and nails from FFR to nail some blocks down to keep the frame from sliding around. The tie down system needs to be fairly durable to withstand this long journey. I used 4 dirtbike tiedown straps and nailed a short length of chain over the front crossmember as a safety. The hood isn't fastened well and needed to be carried inside the truck behind the seat. Some rags to use as padding are handy. My frame rubbed the paint off on the bottom but the factory paint isn't all that great anyway and needed blasting and replacement. The aluminum is fastened by one screw each and also vibrates, knocking off more frame paint. It is conceivable that a panel could fall off, another reason for a full wrap. The assembly rests only on the 4" tubes from the front wheel-well center to just in front of the rear wheel-well, not very long. Mine was so light, my son and I lifted the entire assembly and stepped off the trailer at home but it has a carbon body. FFR is right when they say almost any trailer will work. Good luck.