Here's a trick I read about years ago in a dirt bike mag.

Every time I read a tread that mentions the damage due to a tie down comming loose I think of this.

Place a bungie cord between the loops on a tie down and when the suspension compresses far enough for the tie down to come off..... the bungie cord will take up the slack and keep the hook in place.

I've seen one bike fall off the back of hitch carrier right onto the ground at the end of a off ramp.

I've seen a busted rear window of someone who I told this trick to just 20 min earlier (can't help to feel bad for that one, murphys law)

Just read about gas all over the inside of a enclosed trailer due to a tie down that came loose (that's the one that got me to write this)

cheers