I assume you can't find this person to get the title. You may have bought a stolen car. Did you at least see the title? Do you have the old registration info? While you can buy a junked or wrecked car and transfer the VIN number on the dashboard this is illegal. Also the VIN number is engraved in the firewall under the hood as well as and you can't change that. Go on carfax.com and check to see if the car is stolen and if it is get rid of it.