I did a lot of analysis on Ambient coloring zones as defined in our infotainment filesystem
For those who love to read how I analyse this kind of stuff, read my drive2 blogpost about it here:
Researching GCA (GenericCarAdjuster) Files
My main goal was to find out what mechanism determines which ambient zones are configurable on our devices. Of course, lights need to be attached to the LIN bus, but without the correct zone configuration, you won't be able to configure the zones in the settings screen.