The Koreans post their phone numbers in the corner of their car windshield.
"Why?" you might be thinking.
Well when there isn't much space to park, people often block other people in. Then, when the blocked in person needs to leave, all they have to do is simply call the phone number posted on the car and that person comes to move their car.
How bout them apples?!?!
Some are professionally printed on metal plates...
Some are handwritten on various shapes.
And some people even have two. How thoughtful of them to offer an alternative phone number! :)