To receive this ending, DO NOT BEFRIEND EVE.
You must first obtain both Key Cards and then go through the Lower Levels (second elevator). Once you get to the Third Floor of the Lower Levels, you will attach an Android Reconfiguration Device to an Android. The Android will then open the Systems Door for you. After this is completed, you will see a large garage door. Take this door to find yourself back in the Warehouse. Head outside of the Facility and you will notice that Buck's car is gone. Proceed left, out of the gate, and watch the ending unfold.