In Rage for the PC, PS3, and Xbox 360, there is a hidden room designed like the old PC game Wolfenstein.
During the first mission called Ghost Hideout, after you die and have to use the defibrillator to revive yourself, go to the next area and kill all enemies in the area. Look around for the flat screen tv, and stand to the right of it in the corner. Press the interact button to open a hidden door. There are no on screen prompts to interact with the door.
Inside of the room you will find the Wolf Goblet, which you can sell for $150.
You can’t come back to this mission to find the room after you complete the mission.