How to know if car is unlocked/disarmed

Hello Everyone, a Newbie Here.

What a great site, thanks to everybody who has posted DIY's and who has replied to questions and all the advice's. I couldn't have not done my installation without this site and you folks.

This is what I have done so far
1. Installed Kenwood DNX570HD and CMOS 300 rearview camera

This is what I am trying to do and need some help. I am planning to install a weather proof push button underneath the rear bumper of the car so I can open the trunk by pushing the button with my feet.

I was planning to mimic the trunk release button press under steering wheel when the button under rear bumper is pressed, but the problem is that button works even when the car is locked.

So I am trying to see if there is any wires that I can tap into to tell me if the car is unlocked/disarmed.

This way I can ignore the rear bumper button press when the car is locked/armed.

I am also planning to install the directed pke 2102t so when I am near the car the car is unlocked already and I want to open the trunk when the button under the bumper is pressed.

Any help is appreciated.