A couple of years ago a car overturned in a suburban road near us. The street was parked on both sides, with just enough room left for two cars to pass each other. It was a small to medium saloon car and was upside down in the middle of the road - no skid marks, no damage to other vehicles, and no obvious damage to the car itself. No police presence or onlookers. I stared for a minute and then carried on walking. Later that day the vehicle was gone, as if nothing had happened.
I can't imagine how a car could overturn like that for no apparent reason.