finish the fights... driving, you both think the other is bad, when in fact it might be just a matter of preferences. But by getting mad and stopping the fight, all is left unresolved.
A better approach is to ask her just exactly what is so bad about your driving. After listening to what she says, explain to her that these things are done intentionally because that is how you like to drive. However, since she is a passenger and forced to endure the habbits of the driver, you will compromise on some of these if she will also compromise on some of her driving habits when you are the passenger.
Resutlt is that you both got to say exactly what it was that was bugging you, there was a compromise, the situation is resolved, life goes on with no more anger over driving together.
Fighting is not bad. But not finishing the fight is bad.