The Official Shotgun Rules

Just to give you a bit of background. My mate Li just got a new Nissan Pathfinder. Fully optioned minus the nav system. It's an awesome roadtrip car. So Li's giving 6 of us a ride to watch War of the worlds. What a shite movie that was. I digress.

Here's what this post is all about: official rules for calling shotgun. I'm posting it here for reference so that people know the rules and can adhere to them :)