Don't ride behind or stay very far back from any vehicle that has stuff attached that can fly off.
- Anything on top (Bicycle, Thule cargo box, mattress, canoe, kayak, etc....)
- Work trucks - like a gardener with a pickup filled with all sorts of crap, work truck filled with tools, etc....
- Trailered cars or bikes
The list goes on forever.....
Assume that anything might fly/fall off, hit you and ruin your day will do just that.
I think it was on ADV where I read of a rider who had an oncoming Subaru lose a kayak mid-turn and almost take him out.
In Sturgis in 2005 a rider was killed when a Porta-pottie fell off of a truck in front of him.