Car Alarms: Adding Auto Start Feature, remote car starter, pontiac grand prix

Question
I have an 05 Pontiac Grand Prix GT that from what I have come to understand was supposed to come with the auto-start feature. Currently, I have the keyless entry, alarm and trunk opening on my current keychain from the factory.

My question is this. I would like to somehow incorporate the remote start option to my vehicle. Would I have to scrap all of the features I currently have and goto a new system that has all of these options? Could I have only the remote start installed but have to use another keychain strickly for it? Or, is this a dealer only option to where I would have to get them to do it.

Thank you

Answer
You can have the dealer add the remote start option to the car yes, but in most cases the cost of a factory installed remote car starter is entirely too much money.  Not to mention the pretty sub-par range of a factory remote control.

You can also take the car to a local shop and have them add a remote start to the vehicle and have it activated by the factory remote control if your remotes work when the vehicle is running.  They accomplish this by tapping in to one leg of the door lock actuator.  It monitors the wire and if it sees 2 or 3 (depending on how it is set up and which manufacturer made the system) pulses on the wire it will activate the starter.  

My recommendation is to get an after market starter installed that includes transmitters.  The after market system can control all of the features you describe but with substantially greater operating distance.  When you install an after market system, none of the factory installed options change so you could still use the factory remotes but only for the features that it originally came with.