Behind the scenes of the 'Seinfeld' reunion

Jerry, Elaine, Kramer and George are back after 11 years! Extra goes behind the scenes of the 'Seinfeld' reunion on HBO's 'Curb Your Enthusiasm'.

Three of the four stars of 'Seinfeld' have made guest appearances on 'Curb Your Enthusiasm' over the years. In Season 2 both Jason Alexander and Julia Louis-Dreyfus appeared as themselves when Larry was pitching a new TV show. And in Season 4's finale, Jerry Seinfeld appears, wincing in the audience of 'The Producers' when Larry forgets his lines. Watch the behind the scenes video below.

This season, Jerry Seinfeld, Julia Louis-Dreyfus, Jason Alexander and Michael Richards will all appear as themselves planning a 'Seinfeld' reunion in a multiple-episode story arc along with plenty of other familiar faces (hello, Newman). The 'Seinfeld' "reunion" begins September 20th, 2009 on HBO.