Dont bother trying to 'do something about it' with authorities - you will waste a large chunk of your life for no result. It's just bad luck. It is surprising the amount of stuff you see on the roads these days that has fallen off trucks/utes. Big, dangerous stuff. A few weeks ago I had the car in front of me (ute) lose its whole rear canopy just ahead of me. Scared the s**t out of me. Narrowly missed it while cringing about the almost near 5 car pile up behind me on the M1.