Theres a funny story of a mac laptop owner that set the built in camera to record frames, so that when it was stolen he actually got some pictures taken of the crook flipping it open. Similarly maybe this system should be wifi based, as a small embedded computer, so that whenever it is in range you can interact with it.

For SMS messaging it he uses a go-phone that might be reasonable because I don't like the idea of devoting a SIM card and a regular mobile subscription for this.

Seems way a little bit complicated, I still prefer the kill switch option. Costs you like 3 bucks for a switch from radio shack and some spare wire you have at home, and bam noone can steal it w/o knowing where the switch is.

Sounds like a good candidate for Ycombinator Africa edition.

Cool. He made onstar in his spare time. Nice hack indeed.

As a side note, I really don't want onstar to add the ability to turn off the ignition remotely!

God willing, one day cell carriers will be open enough to do this hack without needing a cellphone.

Interesting concern: What if some malicious hacker breaks the anti-theft system and starts sending it arbitrary commands?

Just a thought. Still, very nice idea.