BRZ factory alarm - Able to add sensors?
 

Does anyone know if the factory alarm system allows you to add a shock\motion sensor? And, is the alarm a separate unit, or is it built into the ECU?

I had the same questions. In asking someone in Japan, the answer I got was a little disheartening. What we have is the Prius alarm system. There is a way to swap out the alarm ecu with one from a Lexus LS, and reflash the stock ecu once the shock sensors have been installed. However, what you'd spend to do so, would be the same cost as what you'd get from an aftermarket alarm with potentially fewer problems.

That's a shame, in my old S2000 it was as easy as running a wire/sensor from the alarm unit--it was built for an additional sensor just not implemented out of the factory. Hoping this was the same for the BRZ