Lost car key replacement: You could call a locksmith, who can come and make you a new key on the spot. In some cases—an unusual or older vehicle—a locksmith may not be able to help. You might need to buy a new ignition lock cylinder and key from the dealer or an independent repair shop. Most vehicles in the United States from 1990 and up have key codes that are saved on file with the manufactures. As long as you can prove ownership of your vehicle a car key can be made with the Vehicle Identification Number aka VIN number. Once a key code is pulled from the VIN number a car key can be cut.