Want to add a method to lock doors from rear of car, when in ready mode.

Hello.

I have a gen2 without smart key.

I would like to lock the doors when in the back (whilst in ready mode) without having to lean through to the front.

I was going to connect an extra switch to the wiring but it is not obvious which wires and the switch is some unusual (to me) sliding mechanism. After testing the contacts it does not seem to be a straight forward switch.

Does anyone know which wires could be connected to activate lock/unlock?

I bought and programmed a 2nd key but it does not operate the doors when a key is in the ignition.

Other options I am considering are a finger bot, servo, or long stick with push/pull to lock/unlock.

Thanks.