A woman got a dent in her car and took it in to the repair shop.

    The repairman decided to have a wee bit of fun. So he told her all she had to do was to take it home and blow in the tailpipe until the dent popped itself out.
 
    After 15 minutes of this, a lady－one of the woman's friends came over and asked what she was doing.

    "I'm trying to pop out this dent, but it's not really working."

    "Duh you have to roll up the windows first!"