A blonde was driving home on the freeway after work when a hailstorm hit, leaving her car covered in dents. She went to a body shop and asked the owner for a repair quote.
Seeing she was blonde, the owner winked at his partner and told her it wouldn't cost anything if she followed his instructions carefully.
She drove home. When her blonde roommate came out, she found her friend sitting behind the car, blowing hard into the tailpipe.
"What on earth are you doing?" she asked.
Her friend looked up with a big smile and a black ring around her mouth. "The man at the body shop said I could save a lot on repairs if I blew really hard into the tailpipe. He said all the dents would pop out!"
"Duhhh," said her friend, "but first you have to roll up all the windows!!!"