When more than 1 1/2 times as many people as intended (rounded down) try to fit into a car. example: 5 people in a 3 seat car, 8 people in a 5 seat car, etc.
1: Dude, we crammed 9 people in my Jeep. We did a total Mexican Taxi.
2: Hey, get the fuck outta my car. This aint no mexican taxi.