Everyone is flocking to the car wash to get the corrosive salt and unsightly crud removed from their vehicles. Noticing that the driver ahead of him had neglected to slide a plastic sleeve onto his rear wiper, a friend of mine recommended that he do so. The guy said no, he didn't think it was necessary.
And of course, on the other side of the car wash tunnel, he ended up minus a rear wiper.
My friend was amused, but he confessed that he had wised up only after losing a wiper under the exact same circumstances.
The motorist in front of me at the car wash the other day was even more careful: he even removed the little magnetic signs from the back of his car.