What is the metaphor for the four-wheeled positioning of a man and a woman?

Metaphorically speaking, it refers to the positioning of the roles of two people in an intimate relationship between a man and a woman. The man as the "front wheel" means that the man should take the lead, leading the direction and rhythm of the relationship. The man is in a more active position in the relationship; the woman as the "rear wheel", meaning that the woman should be in a position to be led in the relationship, the man's dominant role to give cooperation and support. Play the role of following and coordinating; male also as the "left wheel", meaning that the male in addition to play a leading role, but also in the feelings of the female should be given appropriate care and attention. As the car can not only right wheel, also can not be separated from the left wheel of the propulsion; female also as the "right wheel", meaning that the woman in addition to play a role in following and coordinating the role of the man should also give enough care, understanding and encouragement. Like a car, it needs the right wheel to move forward smoothly.