Hello, if this is a factory alarm, this service information may be what is going on with your vehicle. there is some updated parts for the alarm.
All Other Areas (Excluding North America and Europe)
Some customers may comment that the car alarm activates when the trunk is opened with the key. Also, some customers may comment that when they unlock the trunk with the remote key trunk open button, the doors relock.
The RKE operation software may have been erased by electrical "noise."
Replace the remote control door lock receiver. Refer to Remote Control Door Lock Receiver Replacement (Notchback) in SI.
Receiver Asm, R/Con Dr Lk & (North America)
Receiver Asm, R/Con Dr Lk & (Europe and All Other Areas, Excluding North America)
Ok, from what i have found, and the information you have gave me. it sounds like the door tamper switch has either been damage from theft attempt or the switch is now sticking. here is a description on how the the switch works.
Theft Deterrent Switch (Tamper Switch)
The front doors and rear compartment are equipped with tamper switches. The tamper switch attaches to the lock cylinder. The tamper switch activates by movement of the lock cylinder. The tamper switch activates under the following conditions:
Additionally, use the tamper switch in order to disarm the system. The switch grounds the disarm input to the remote control door lock receiver (RCDLR) when the lock cylinder turns in order to unlock the door. The switch is serviceable. Remove the switch from the door latch in order to service the switch.
Mechanical failure and/or corrosion on the switch may cause the system to self-activate intermittently. Inspect the lock cylinder for looseness if this happens. Any movement of the lock cylinder with this switch can cause the switch to activate the alarm. One possible cause for this problem may be a lock cylinder retainer that is not firmly installed to the lock cylinder. Reinstall the lock cylinder retainer or replace the lock cylinder retainer with a new retainer in order to correct this problem.
If the turn signal lamps flash once when the LOCK/UNLOCK button on the transmitter is pressed, that means the content theft security system alarm was triggered.