Prepare the glasses by cutting a small slit in one of the lime pieces. Run the lime around the edge of each glass. Dip edge of each glass in a shallow bowl with the salt.
In a blender, combine sweet and sour mix, triple sec, tequila, and Grand Marnier. Blend until smooth and place in the fridge to chill until ready to serve or fill glasses right away with ice and pour into each glass. Serve with a lime wedge.