That's under his steering wheel not under his seats.

Many years ago, I was told about carjacking "prevention" method of an aftermarket alarm system. A button must be pressed upon exiting the car then at a set period of time the alarm system would kill the engine. The idea is to let the carjacker drive away and then kill the engine, rendering the car immovable yet the carjacker is far away enough so not to come back to the driver and force the driver to restart the engine.

I'd say try it in a safe area where you can pull over in the case of power loss.

That button is to set the sensitivity of your Karrtrack alarm. It is an option installed at the dealership, but by the Karrtrack company, not the dealer. Your alarm can be activated to track your vehicle using GPS on Karrtrack's website if it is activated. I suggest you contact them and give them your VIN to find out. Mine on my Z is not activated for tracking, but the alarm is. I also have it on my SRT and that is active for tracking. Install took all day because they hide the GPS tracking device very securely. Even the dealer doesn't know where it was placed. If my SRT alarm goes off, I get a text message immediately and I can track it on my phone if need be. I used the tracking when I had my vehicles shipped from CA to NC. Kept tabs on the truck driver :) It is actually a great thing you have on your Z!