WARNING: This page is about a different car, the 2011 Chevrolet Cruze. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Power, Ground, Serial Data, Antenna, and Display Wiring Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 2: Door Speakers (without UQA) Wiring Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 3: Amplifier (UQA) Wiring Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 4: Door Speakers (UQA) Wiring Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 5: Center Speaker and Subwoofer (UQA) Wiring Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 6: Navigation System (UYS) Wiring Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 7: Audio Input (without KTA) Wiring Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 8: Multimedia Player Interface (KTA) Wiring Schematic