Hello Phil,
to find a way to open/close the Crossfire's central locking system and enable/disable the alarm was the last missing goal for my Skreemulator. I this video you can see how I open/close the Crossfire and enable/disable the alarm with a Arduino. So I could now (expecting the obd diagnose) fully emulate a skreem module.
I'm actually designing the hardware and the PCB, I hope to get a working prototype this month. I have also to optimize and write some parts of the software, I hope I get this also ready this month. Then I will search for some people to make a beta test.
I think in the middle of this year I could sell my Skreemulator.