If a man wishes to buy a second car for his wife to use, with his own money, and his father tells him not to, is it right to go ahead and still buy the car, which he sees as a requirement for her movements, even though he knows that this would displease his father?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

If the father has a sound reason for refusing that, as if he knows that this will affect your spending on him, or if you will not be harmed by not buying the car, then it is incumbent upon you to obey him. This is the criterion for obeying one's parents, i.e. obeying them is obligatory regarding what involves benefit for them without harming their children as we have pointed out previously in Fatwa 131695.

However, if the father does not have a sound reason for refusing or that he has one but you will be harmed if you obey him, then obeying him will not be obligatory.

In any case, it is necessary to treat the father kindly and make him feel happy and contain his anger with wisdom for there are ways to win the hearts of old people to which Allaah The Almighty guides whomever He wills.

Allaah Knows best.