Being in Norway, I'm used to the "age before beauty" rule. Had to read up on calling shotgun, there's a lot to take in. I'll try hard to bide by number 16:
16. If someone has successfully called shotgun, they have the right to the front seat. They do not have the right to correct the driver on their navigation skills ("take a left here you ********!") or driving ability ("I'd be in third gear if I was driving"). If the passenger does this, then they forfeit their position as shotgun holder.
Also crossing my fingers that Jack Sparrow's not jumping on the wagon this weekend:
21. If one of the potential occupants of the vehicle is dressed (convincingly) as a pirate then they are given automatic shotgun. In the event of more than one pirate being present, a sword fight shall determine the successful shotgunner. This is known as The Pirate Rule.