Is it permissible for a father to buy a car for his son from inherited wealth and register it in the son's name?

The fundamental principle is equality among children in gift-giving. However, it is permissible to favor some of them for a valid reason that necessitates it, such as need, disability, or knowledge, not merely out of favoritism. If the son is in need of the car, it is permissible to grant him its use without transferring ownership to him, so that the car remains registered in the father's name, because what is permissible due to necessity is limited by the extent of that necessity.