This particular activity is best left to the locals, and even then it is best not to watch. It is also advisable to ignore any 200ft drops on either side of buses, turn a blind eye to gargantuan oncoming trucks as they hurtle towards your vulnerable rickshaw and completely forget about the fact that your driver has never had anything resembling a driving lesson and is probably well into his second flask of whisky.
As far as etiquette goes, it seems that anything is acceptable as long as it is accompanied by several loud blasts of whatever is going by the name of a horn on your particular mode of transport. This may include overtaking on a hairpin bend halfway up a mountain; driving between oncoming cars before swerving to dodge a camel; or running over dogs - the list is endless, but all okay with a couple of honks before, during and after the manoeuvre to the grating background of Hindi film music. It is also compulsory to laugh after such stunts - the more dangerous, the more raucous the laughter.