My daughter purchased a 2010 Mazda 6 and we have had many issues with the battery. After time, I noticed the alarm issues went away when we did not lock the car. Then some neighbor kids played in car without us knowing and trunk was left slightly ajar and killed the battery. When we charged it back up, we decided to lock the door. For about 3-4 weeks, no alarm. Then it started going off again, so we unlocked the doors and no alarm. However, she is taking to college in Fall and we want to be able to lock the door. I suspect it is related to sensors or actuators as the alarm only goes off when it is locked. The car cost under $3000, we do not want to spend a fortune to get fixed. Any suggestions????