Well, that's what I've heard, and it makes perfect sense. The beginning of the movie starts out with 0 connections to Desperado, except that it has The Mariachi. Also, he goes to pick up his guitar case from a friend, which he had at the end of Desperado. But, even if it is the 3rd, it sucks and I suggest that you do not see it, unless you want to pay out a few dollars for a laugh here and there.

So this baby seal walks into a club.