a blonde gets caught in a hail storm, and her car gets dented all over. the next day she takes it to a shop, the mechanic sees shes a blonde, and decides to have some fun. he tells her to go home, and blow into the tail pipe. she goes home, and blows! nothing happens. she blows again, even harder, and again, nothing. she tries SO hard, she faints! when she wakes, her roommate (blonde) is standing over her. she asks "what are you doing?" so the 1st blonde tells her, the roommate laughs, and says "duh, you have to roll the windows up!

i don't get it