Cadillac Margarita #2

1 1/2 oz Tequila
3 oz Sweet & Sour Mix
3/4 oz Triple Sec
3/4 oz Lime Juice
Float Grand Marnier

Shake tequila, triple sec, sour mix, and lime juice with ice. Pour
over ice in salt-rimmed margarita glass. Float Grand Marnier on
top. Garnish with slice of lime if desired.