This may be an urban legend, but a friend told me that a friend of hers "dumpster dove" in the Rio Grande's garbage many years ago to figure out which ingredients they used in their margaritas. He found many bottles of these ingredients and then took some drinks home and reverse-engineered it. Whether it's true or not, it tastes like their margs and packs a kick.

Parts    Ingredient

3          Jose Cuervo Gold Tequilla
1          Juarez Triple Sec
3          Duffy's Lime Juice (Rose's OK too - they used one called Beiches, but it apparently was bought by Duffy's)
1          Water
2          Apple Juice (the clear kind)