Although this is a link and hosted by another site, I did design the circuit and write this article myself. Basically people with the Subaru OEM alarm must cut the shock sensor feature because the idling car will set off the alarm while it's turbo timing. This mod adds a relay to trick the car to arming it after the ignition shuts off. When the article was written, it was the only one of it's kind.

CN: mod allows shock sensor functionality