Been there. Sucks. All my usual ways of calming myself need peace and quiet so now that I have kids they are useless. I just swallow the rage along with a few cocktails and pizzas. Maybe a bong hit. Healthy? Probably not but it'll have to do for now.
Fighting in the car (to the point of suicidal feelings) on the way to see Santa... sounds like my childhood. All the joy was sucked out of every event by my parents escalating some petty disagreement into a raging fight, usually in the car, but sometimes right before we left so we could spend the car ride in oppressive, nauseating silence. I'm sure that kid had a great time pretending to have fun visiting Santa.
This is the kind of behavior that the Stranger thinks is cool. You can do anything you want. Just say you are sorry, and then you don't have to be responsible for the damage.
/projection