In my years on the road, I had three close calls with flying objects, a lid of a bbq took out my bonnet and windscreen on an 80kmh highway in Adelaide, stopped the offending car and trailer to find I knew the bloke thru work.
Second one was a wheel and tyre which bounced of a trailer drawbar on a 110kmh stretch of the Eyre Highway, managed to avoid that one.
Thirdly, a steel bar came of the top of a semi, travelling in the opposite direction, 100kmh, hit the number plate, grill, bonnet and windscreen of my Commodore wagon, punched a hole clear thru the bumper and number plate, creased the bonnet and broken windscreen, plus the obligatory Shit filled undies.