i have yet to travel in a cab that has its speedometer working. i guess since they're always the slowest things on the road they don't need to figure how fast they're cruising.
it can get real frustrating to sit in the back of one while every other vehicle on the road overtakes you. if you complain about the lack of speed then the guy driving the contraption is likely to give you the evil eye.
other traits common to the practitioners of this profession include dangling one arm outside the window and steering with the other. this no doubt makes for a cool self-image but the limp arm looks definitely ridiculous to passersby.
and i suppose that keeping spare change to be returned to paying customers is a big no-no in their user manual.