never heard of one and i don't think you really should scare the passengers.
What i read is a ghost story on most dangerous road in Bolivia - North Yungas Road. Local drivers and people know about it.
It is believed there's a bus - which full of passengers drove of road and fell into the valley below - "roaming" on that stretch of road. Sometimes at night drivers can see headlight beams before the corner but after the corner there's nothing there!
and than there's THE GHOSTLY NO.7 BUS http://seminars.torontoghosts.org/blog/ ... shall_meet