Tossup between:

• Seeing a sporty little car neatly stacked on top of a full-size sedan at the local shopping mall. Owner had floored it, jumped the curb, and somehow managed to climb atop the sedan. It was remarkable just how little damage there was on the Sedan, relatively speaking.
• Seeing a truck on the highway shoulder, which had somehow managed to roll itself on its side facing the wrong direction. Like, 180 degrees around into traffic and on its side. Somehow it didn’t look like other vehicles had been involved.