My 99 has the factory alarm, on occasion it seems that the alarm will randomly go off. I have had this happen several times and I am not 100% sure what causes it. There is only one thing that seems to be consistent, 6 out of the 7 times that the alarm has randomly gone off (while I have heard it) my blackberry has been sitting in the cup holder while the alarm is on (doors locked). Has anyone else had this or something similar happen?