Some of them are already enacted in my car, and with a friend we're talking about putting more into effect .
I wrote my own rules of shotgun, back when I was the only one of my friends who had regular access to a car. They also include the privileges and duties of the shotgun passenger. I'll see if I can dig them up.
Funny, yesterday I called shotgun. I showed my cousin this as he walked by [as he wanted the front seat yesterday but I got it because of shotgun], and he just punched me. I just laughed as he left.