Hanging on the (open) back door: one foot on the step, the other on the handle of the door, while clinging with both hands on the top of the door frame, thus travelling for many hours...

And, of course, when the back of the car is full, one can always sit on the top or hang on the side of it... Locals say that Indian cars need a good horn, good breaks, and good luck. Good driving skills are here not mentioned...