If you have pwr. door locks, you can buy a receiver that will send an open/lock electrical signal to the pwr door actuator with a remote key pad. We installed one in a Marquis...fairly simple and worked well. It's been a while but I guess they still make them - we found it at the Mercury dealership. Otherwise, I would think it pretty much cost prohibitive to install the standard five key door pad along with the whole works. Bob