Hello, I just got the Clifford RSX3.5 installed yesterday. It seems like a great alarm. Mine has the autostart feature. I went to clifford's website and I believe the 2.5x and 10.5x do not have the autostart. I figured if I was gonna pay 300 for an alarm that I might aswell pay another 125 and get it with the autostart. My friend has had the same alarm as me for about a year and its still working great. I am not sure but he might have a slightly older model.