I have some personal car etiquette rules-
1) Passenger gets control of the radio. I need to focus more on not running anyone over and yelling at the bastards that cut me off than to fiddle with the music.
2) On road trips, passenger retrieves coinage for tools and eats first then feeds the driver. Again, hands are busy and it's keeps the spillage down to a minimum.
3) Driver ALWAYS opens the passenger's door. In turn, passenger should open the driver’s door once he/she is in the car.
4) Back-seat drivers are KOS and will be ejected from the vehicle via ejection seats unless they are the designated navigators.
5)"*mmmmmmmkhhheck* This is your captain schpeaking. We are experiencing some !!Tuuuurbulllaaannnnnccce!!!! *shake the back of the seat"
This action if forbidden to inflict on the driver. The passenger, however, is fair game.
6) Thanking the person who let you in by waving is a much-required courtesy. It's also a good idea to apologize to someone in this same manner if you happen to cut them off.
7) Florida drivers should be shot for not using their blinkers...damnit. How the eff am I going to know you are turning if you don't use your friggin’ blinker... bastards.