Answered my own questions with google search, there is a seperate process for programming the remote and the key. One thing to note, I bought two of these, successfully programmed both remotes, had both keys cut and tried to program both keys. One worked great, the other will not program. When I tried the keys before programming, the car wouldnt even crank. Now (with the one that didnt work) it cranks but will not start and the Securilock light flashes. Must be a defective key or maybe I did something wrong, but the same exact procedure worked for one of them. No idea how to fix this one without a dealer trip or ordering another key. But at least the two originals and one of the two flip keys I ordered works.
Step-by-Step Programming Instructions:
1. Turn ignition from OFF to RUN 8 times within 10 seconds, with the 8th time ending in RUN. Door locks will cycle to confirm programming mode.
2. Within 20 seconds press any button on first keyless remote. Door locks will cycle to confirm programming.
3. Within 20 seconds, press any button on second keyless remote. Door locks will cycle again to confirm programming.
4. Turn ignition to OFF. Locks will again cycle to indicate end of programming mode.
Step 1 - Assemble your keys. Have at least two factory-programmed keys and all of the spare keys you wish to program close by before you start this procedure.
Step 2 - Insert one of the factory-coded keys into the ignition switch. Turn the key to the "On" position for between 1 and 10 seconds, then turn the key to the "Off" position and remove it from the ignition.
Step 3 - Insert the second factory-programmed key into the ignition switch within 10 seconds of removing the first one. Turn the key to the "On" position for between 1 and 10 seconds, then turn the key to the "Off" position and remove it from the ignition.
Step 4 - Insert the key to be programmed into the ignition switch within 20 seconds of removing the second factory-programmed key.
Step 5 - Turn the key to the "On" position for at least 1 second to program the key. Turn the key to start the engine.
Repeat the entire procedure to program additional keys.
If you only have one factory-programmed key, you cannot self-program a spare key. You must take your vehicle to a Ford dealership to get additional keys programmed.
If the engine will not start using a key that has been just programmed, take your vehicle and the key to a Ford dealership for assistance.
If you have no factory-coded keys for your Mustang, you must have your car towed to a Ford dealership where they will erase the current code from the computer and code new keys to your car.
According the Ford, use only SecuriLock keys available at a Ford dealership in your Mustang.
Items you will need
Spare SecuriLock key or keys
2 factory-coded keys