Back in Austin, Trudy's has an epic drink called the Mexican Martini. Epic enough such that there's a relatively strict 2/person limit. Luckily, there are multiple Trudy's in town...
The recipe is somewhat contentious. Many have tons of orange juice and even sprite in the recipe, but I remember hearing from a trusted source that there was definitely a bit of rum in the mix. You're aiming for a strong and slightly briney margarita, shaken and served up.
Juice of 2 limes
3 oz tequila (or split with mezcal)
1 oz cointreau
1 oz rum
1 oz orange juice
dash of olive brine