Who is the girl that flashes Joe Dirt

If you mean the girl that Joe ordered to flash her front, unfortunately she is uncredited in the movie. There are rumors that she was a Mexican model, while others say that she was Karen McDougal. However, according to IMDB Karen was uncredited as the Taller Brunette Lifeguard.

Joe Dirt (played by David Spade) is about a janitor with a mullet hairdo, acid-washed jeans who works as an oil weller. He's on the search for his parents who abandoned him when he was a baby at the grand canyon. As he travels about, his misguided search takes him from one hilarious misadventure to another.

From TMZ, David Spade dressed up as foxes for Halloween this year, from the wildly popular viral video "The Fox (What Does the Fox Say)" by Ylvis. Find out more here.