Hello, the green copy of the mortgage for a car loan is usually directly mortgaged with the lending institution. If the car loan is processed at an auto finance company, then the green book is mortgaged with the auto finance company; if the car loan is processed at a bank, then the green book is mortgaged with the bank. Of course, the mortgage registration is handled at the Vehicle Administration Office, so after paying off the car loan, you still need to go to the Vehicle Administration Office to go through the mortgage cancellation procedures in order to get the green copy back. The so-called green book refers to the "Motor Vehicle Registration Certificate" of the vehicle, which is of the same nature as the "House Property Certificate" of the house, indicating the ownership of the vehicle and house.