BestKeys 2008 Mercury Grand Marquis Replacement Uncut Transponder Ignition Car Key Huge savings over dealership prices! Programming this key requires 2 working unique (not cloned) keys. If you do not have 2 working unique (not cloned) keys you will need to have the key programmed at an automotive locksmith or dealership. We will provide a link to our website with Free Do-It-Yourself programming instructions with your order. YOUR KEY SUPPLIER is the only authorized seller of BESTKEYS products. All warranties will be voided if bought from any other sellers.