Who owns this rental car?

The owner is the rental company. You are responsible for any damage that happens while you have it. Unless your friend is listed as an additional driver on the policy, he is not covered and can not drive the vehicle.

The car rental company owns it; it is their property. They are just letting you use it temporarily (that's what renting means).

As far as who is more responsible for the car between you and your friend while you're renting (in other words who would get in trouble if something happens to the car), it's you, because it's your name and insurance and credit card.

The car rental company owns the car, idiot. If your name is on the rental contract then you are the authorized driver.

The rental agency owns the vehicle until they sell it.

But since the rental agreement is under your name, you are responsible for this vehicle until you return it to the rental company.

The rental company.

The proprietor is the lease organization. You are accountable for any harm that happens while you have it. Unless your buddy is detailed as an extra car proprietor on the plan, he is not protected and can not generate the automobile.

Legally you're responsible for it but neither of you own it