What is the ruling on sending money to the husband's father to buy a car while we are living abroad?

Sending money to the husband's father from his son is an act of righteousness and kindness for which one is rewarded, especially if the father is in need. The wife should assist her husband in this. If the wife does so from her own money, her permission must be sought. If she grants permission, it is a kindness for which she is rewarded, and it will draw her closer to her husband and elevate her status in his eyes.