To answer the first question in this thread, yes the factory system is a true alarm. It has keyless entry, anti-theft, and an audible and visual alert system. This is what makes a "alarm" complete. Otherwise it is just an anti-theft that has starter disable, or just a keyless entry system.

I have been very interested in the chirp thing along with everybody posting questions here. I don't have time to open the cowl just to look at the siren, so I will have my buddy that owns a body shop order both part numbers for me. When I get them, I will try them both, see what the factory one is, let everybody here know the results, and send back the other siren. SO, this should put an END to this topic with a definitive answer.