Hello, I have a 2011 Mazda 3 with all the options. I am having an issue with beeping noises. Every time I lock my car or open the trunk and then shut it while the car was already locked it beeps 20 times. The beeping has the same tone and rhythm as if you walked away with the key in your pocket and the car is running. Any help would be greatly appreciated!

 

2013 Mazda 3 / No warning lights / 20 beeps after I lock the car / Perhaps because the car thinks there is someone in the car, but I do not have anything on the seat / am searching the manual but not finding this / Glad to see someone else is having the same issue, but wondering if someone has found a cause / Not comfortable because am afraid something may be running the battery down / Please share your experience/ideas!!!