So, having just forked out for a new passenger wing mirror due to the old one corroding so much that it started to fall off, my old Jag has now developed an alarm fault.

When I return to the car and open the boot, then close the boot, the alarm will go off within 30 seconds. I can unlock, then lock the car to silence it and it stays off. It would appear it is the re-arming of the alarm that is causing an issue, so this only happens when the car is locked and armed and I open, then close the boot.

Originally it happened a couple of times over a week, but now it seems to happen every time!

Any idea why this might have started to happen and what could be the cause?

I'm assuming this wouldn't be related to removing the passenger door trim to replace the wing mirror i.e. something has been disturbed?

Thanks in advance.