I havent done a RSR in a newer taurus, all the Remote Starts ive done in them I was adding a viper system on top of a DBALL(or flcan I cant remember) So I never had to lose a key for any of my installs.
On that note, I know when doing vehicles with a similar setup, or using the old 556U module, you needed to wrap the wires around the transceiver, not just place the coils on top of it.