How to get the mystery box on the first door you open.
(This cheat does not work on xbox 360 live)
1. go on kino der toten
2. open one of the doors
3. if the box is not in there pause it and restart
4. open the same door again if the box is not there keep restarting and opening that same door
5. when you open the door and the mystery box is there when you die don't restart just let it restart for you
6. open the same door as all the other times and it will be there
And basicall what he said is, keep restarting the map until the mystery box is where you want it, and then if you die, just sit there and wait for the next round to start rather than forcing it to and it will be in the same place every time.