This is an actually somewhat useful post I think. I've always tied off to a I guess you could say "unsprung" part on the quad. Spindle, or control arm next to the spindle, and usually axle or somewhere around the carrier. I figured the quad with no one on it shouldn't bounce as much goin down the road as it does with my fat ass on it. That leaves no chance for things to move around when the suspension does move and takes tension off a strap. Keeps the wheels planted on the trailer.
Any thoughts?