What is the ruling on obtaining a loan from Al Rajhi Bank to purchase a car, where shares are sold to the customer instead of the car, so that he may sell them or the bank may sell them for him?

If the shares of the company or institution you wish to buy are permissible (halal), there is no objection to purchasing them in installments. You may sell them to others after you own them, or the initial seller may sell them to you as your agent. It is stipulated that there should be no other impediment to the sale, such as Gharar (excessive uncertainty) or Ghish (deception), and that the company should not deposit its funds in interest-based banks and earn interest from them.