It could be down to the interior cooling down as a lower
or faster rate than the outside...causing thermals inside
the car which then sets off the interior sensors.
Sound's daft, but it does happen.
It's like a car windscreen..it can be fine during the day but
crack/split at a tiny stone chip when the temperature changes
between the inside and outside of the glass.
Anyway...to test this out....on the centre dash switch panel
are 2 images of little cars...one level (for the internal sensors),
and one tilted up (for vehicle towing/being jacked up..as in stolen).
As you exit the car press the 'level car' button and it will start to
flash.
Close the door/s, arm the alarm, and see if it goes off as it has been.
If it doesn't work..let us know and we'll see what else we can come up
with to help, ok.
PS...I press that button if I park in an area where there are heavy
lorries rumbling by...or buses ..of noisy area's like near an airport
or railway station/tracks etc, as those things trigger the alarm to go.
But try all the suggestions...you never know which one it might be.
