WARNING: This page is about a different car, the 2003 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Inside Rearview Mirror Connector End View
Courtesy of GENERAL MOTORS CORP.
Fig 2: Vehicle Interface Unit (VIU), C1 Connector End View
Courtesy of GENERAL MOTORS CORP.
Fig 3: Vehicle Interface Unit (VIU), C2 Connector End View
Courtesy of GENERAL MOTORS CORP.
Fig 4: Vehicle Communication Unit (VCU) Connector End View