How to get a new car key made?

I bought a 2006 Ford taurus used about 6 months ago. It did not have an original key but it has a remote start system and a spare key without a chip that I can turn the ignition to the on position to drive the car. Recently I've been having trouble with the remote start/car alarm that was installed but I took the car to a dealership and they said they could not make me a working key because they did not know what the car was programmed to with this after market alarm/remote start. Is there a way to find out? I know the guy I bought it from said the chip was in the car so it could start and there's this thing on the visor that looks like it could be it.

Added (1). Also They said removing and and then getting a key they could not guarantee would work

Contact a COMPETENT dealer, or even a competent locksmith. An minimum, they should be able to get the FACTORY specs from Ford, and program a new key by UNPLUGGING the aftermarket system. IF they can't get specs from BOTH Ford AND the aftermarket manufacturer to allow them to properly program both, I wouldn't trust them to check the air in the tires.

Note: Any SEMI-Qualified locksmith will LAUGH at liverhyen2003. 'His' method is nothing more than following the MANUFACTURER'S instructions available online.