Three incidents in my time, but none where my car was damaged.
Way back in the mid 60's, my folks took us for a caravan holiday to Port Macquarie. A hired van was hooked up behind the ol' HR and off we went.
Got to Taree, and in those days, you had to drive through the town. We had come down the hill past Purfleet and just crossed the bridge over the Manning. We approached the lights which were red and the old man hit the picks. Next thing, "bang!" followed by a strange feeling as the van decided to push us forward a bit. The welding on the tow bar had given way and the goose-neck, ball and van dropped free just as we slowed down for the lights. Wouldn't like to think what might have happended if it had been a few k's earlier.
Second incident. Following a mate in his old EK when his bonnet suddenly flies open. He's all over the place trying to slow down and remember what was in front of him just before it happened. No damage apart from a rooted bonnet.
Third one. F3 at the Hawkesbury a couple of years ago. My son was driving his VZ home with me as passenger. Late at night and pitch black. We ran over a bloody mattress - obviously flown off some dill's trailer or roof-rack and left there.
A mattress at 110 kph is nothing to run into. They might be nice and soft to lay on but at that speed, it might as well be a brick wall. Only damage was to the lower valance panel fortunately as the car seems to have passed over it after the wheels struck.