Why should I

A blonde tried to sell her old car. She was having a lot of problems selling it, because the car had 250,000 miles on it.
One day, she told her problem to a brunette she worked with
at a salon. The brunette told her, "There is a possibility to make the car easier to sell, but it's not legal."
"That doesn't matter," replied the blonde, "if I only can sell the car."
"Okay," said the brunette. "Here is the address of a friend of mine. He owns a car repair shop. Tell him I sent you and he will turn the counter in your car back to 50,000 miles. Then it should not be a problem to sell your car.
The following weekend, the blonde made the trip to the mechanic.
About one month after that, the brunette asked the blonde,
"Did you sell your car?"
"No," replied the blonde, "Why should I? It only has 50,000
miles on it."