Normally at this time of the year i tear out all of the car audio gear and place in storage inside were it is nice and warm. I have heard about people blowing voice coils from using their equipment in -10,-20 winter temperature even though they thought the temperature inside the car was warm enough with the heater on to play the stereo at moderate to loud levels.
When all my gear is out i would disconnect the alarm. My question is this.......I was told that it is common in the winter months for car alarms to go off due to the battery losing a little voltage when sitting overnight in frigid weather. Is this true??? I remember years ago i had a problem with a car alarm going off in the summer months for no apparent reason, later to discover that i had a weak battery that was the culprit.