In a blender, combine the red wine, lime juice, orange juice, and triple sec. Add a few ice cubes and blend until smooth.
In a separate container, mix the limeade concentrate with the tequila.
Prepare your serving glasses by running a lime wedge around the rim and dipping the rims in salt.
Pour the blended sangria mixture into the glasses, filling them halfway.
Gently pour the margarita mixture over the sangria, creating a layered effect.
Garnish with a lime wedge and serve immediately.