When you are too drunk to drive and make a taxi take you to get tacos.
I'm too drunk to drive, let's get a mexicab.
A taxi service reserved for mainly people of mexican descent, and there is a taco/burritto/tequila/chimichanga/nacho bar in the backseat,so in other words,it is the only time when being mexican is a good thing. It was founded by Jim Sanchez in 1975.
Non-Mexican:Yo we should grab a cab back.
Mexican:No im gonna grab a mexicab,its better.
Non-Mexican:Sweet,ill come with you.
Mexican:Sorry,youre not a mexican,so it sucks to be you.
Non-mexican:that is the first time that sentence has ever been said.