my friend's window was smash and the alarm didn't sound...I was told it only off if the any of the doors are opened. I need to upgrade my 2013 accord alarm with bump or impact. I would like to use my existing remote. OEM upgrade? Any suggestion will be helpful>

thanks
Mytman

 

I've moved this to the audio section - should get better answers here.

 

The factory alarm is a closed system.

You could trick it by installing external components and a relay that simulates the door opening.