Who knows what these things are? Under back seats...

[GreenBravada]

Under my back seat, I found this plug (with a green cap?) and one orange wire purposely clipped?
What and why, please? Pics a,b,c with green plug:

Then there's the big box with two of the three cables pulled out. I assume this is the OnStar module, and I assume it is obsolete. Is there anything other than OnStar going in or out or through this box? (I notice that my rear door speakers are not working, by the way.) Pics d,e,f

Finally, this little black wire that is actually a shielded cable under the back seat and also near the gas pedal. I'm guessing this is from an add-on rear camera or something like that added by a previous owner. Any guesses? Pics g, h

 

[GreenBravada]

I see in the schematics that there's a Body Control Module behind the driver's seat.
And I see that battery power comes through an orange wire.

 

[GreenBravada]

Okay, so I see that the electronics package behind the driver's seat is the body control module BCM, some fuses and other brainy bits.

I also see that the box behind the passenger seat is the OnStar box and all the plugs are out to disable it.

I see that the green cap on the plug is actually a connector that connects the wires going into the plgu in some way. Removing it cycles the door lock with the car turned of. But it seems as if the orange wire that is cut is the 12v battery supply that would power something. The OnStar box?