I don't know a thing about the G62 engine. This is just a thought. Since you have a mechanical kill switch, a modification may be possible. Wire into the toggle switch circuit a micro switch. The micro switch can then be activated by a servo. Install the mod on a servo tray so all components are solidly attached.

The micro switch should be a normally open switch. This allows the ignition to function. The servo closes the switch which grounds the circuit shutting down the engine. This is all an assumption on my part as I think this is how the engine ignition would work.

A test trial on an an engine stand will let you know if this is a viable option. Keep safety in mind. All components MUST be properly installed and flawless in operation. Again just a thought.