On this note I, during high school, worked at a large multiplex movie theater for about a year. During my shifts we had three car fires break out in parked, unoccupied cars. This was considered totally normal by both my employers and the fire department.

This stuff is clearly happening all the time.

This. A coworker's engine burst into flame for no apparent reason as he was commuting to work a few years back. Nobody died, but the car was a total loss.

I think this is relatively common, too. In my life I must have passed a dozen cars burning on the side of the road.