If you were a 'fly on the wall' in my car, this is what you would have heard today:
(Princess, 6 years old) "MOM! MOOOOMMm! Brother won't let me talk. Why does he get to talk and I don't? How come you listen to him but not me? When will it be my turn?"
(Mom) "Just a minute. You interrupted, Brother was talking first and when he's finished then you can talk, ok?"
(Princess) "OK. But I just want to say one thing."
(Mom to Brother) "Do you mind if princess has a turn? You have been talking for the last three miles. Let's give her a turn now, ok?"
(Brother) "O.K. But she didn't say "Excuse me."
(Mom to Princess) "Can you say excuse me, please? Brother is right, that is the polite way to show you have something to say."
(Princess) "O.K. Excuse me?"
(Princess) "I forgot what it was I wanted to say."