I was fooling around with my stock bose "trunk" mounted system today, the big black plastic space hog, and found two connectors on it, but only one was connected.

The first one was a black harness coming from the front drivers side of the car, connected to a green harness on the black plastic space hog.

The second one was grey, coming out of the black plastic space hog, and wasn't connected to anything. Is is supposed to be?