HEH! I remember the busses in Mexico City! More mini-busses than the long ones we get here in England.
The drivers would drive like racing car drivers, usually there's some guy who'se helping let people on and off the bus who stands of the step of the door - I'm surprised these guys don't go flying when the driver takes a turn. These guys try to convonve you to use their bus instead of the one next to them!
Then when you get on, everyone on the bus smiles and says hello, that's so sweet. The driver usually has a radio on at full volume, a mini church altar on his dashboard, and of course, if he doesn't beep his horn at least 20 times between stops, then you know there's something wrong. Finally, I'm sure the driver and assistant must have bets as to whether or not they can re-arrange the seating of the passengers by racing over the speed-humps as fast as possible!
Not forgetting that a bus ride is an opportunity for some shopping, you'l never be short on things like gum and phone cards!