Phase one: Cut the wires or traces to the kill device, or fry it with a high-frequency discharge. This will be made illegal, and interlocks will be introduced such that such a simple attack is well nigh impossible.

Phase two: “Mod chip” type addons which integrate themselves lamprey-like onto the system and subvert it become available from black fabs in China and elsewhere. These will be made illegal, and distributors of the devices will face prison and fines.

Phase three: Reverse engineering and firmware cracking into the killswitch devices will enable installation of null, bypass, dummy or other code to defeat its function. Extra functions may even be found able to run in the processor/memory space thus liberated. These will be made illegal, and the government will mandate manufacturers to take more stringent security measures in hardware and software design. Hackers release first working Ubuntu distribution for Big-Brother-in-your-Car platforms.

Phase four: Chip-etching and electron microscope attacks against “secure” hardware enable discovery of design flaws, manufacturer backdoors, debug interfaces and other points of weakness. Exploitation devices and code take advantage of these, and are made illegal.

Phase five: As the hardware technology becomes tougher to crack and exploit, other avenues will be employed. In the connected future it will be an easy (though non-trivial) matter to play man-in-the-middle on a vehicle-wide killswitch network by sending periodic challenge/response authentication datagrams via p2p networks to black service providers who deliver a simulation of the supposedly cryptographically-secure “keep running unless these messages quit coming” deadman switch mechanism, either for profit, hobby or underground reputation cred motivations.

For info on how this last phase is currently playing out in the world of digital satellite television, google “gbox”, “newcamd” or “newcs”.