4-Wheel Drive

A man has been planning to buy his first new car for a while.  He also wanted this car to be a 4WD SUV.  After saving enough money, he got his dream car.  While driving home happily, he suddenly realized that he was still living in apartment building without his own parking garage.  Parking his baby outside is surely unsafe in the neighborhood.  This greatly damped his excitement.

Having no choice, he parked the car along the street side and reluctantly went home.  He did not get good sleep the entire night worrying that someone could hit his car.  He got up early next morning and went down to check his car.  The car was still the same new look and he felt released.  However, when he came to the back side of the car, he found a childish writing "= 16" behind the 4 x 4 metal sign.  He was upset with such childish trick.  Since it was written in paint, he had to take the car to dealer for repainting that part of car body.  The same story happened the second night upsetting him even more.  

Thought about what could stop such child act for a while, a smart idea suddenly stroke him.  He ran to a sign factory asking them to make a nice metal sign "= 16" with matching font and style. Then he carefully mounted the new sign right behind 4 x 4.  "Ha, what else you little devils can do?"  He went home and had a good night of sleep.

The next morning, he went to enjoy his new baby.  Surprisingly, he found a "check" sign is painted above his new sign.