The forum members of the German fan club website have picked this location, it's supposed to play Queen music on Sunday:
The Lucky-Inn
Marzahner Promenade 45, 12679 Berlin
Leave the Velodrom at the main entrance. There are two big elevators leading to the public transportation - the German fans meet there at the elevators, you can join them, your ticket is also a tram ticket
By tram you take the M6 to Riesaerstrasse, the stop is :Freizeitforum Marzahn
here is the google map for cars link
I hope to meet you there.
@ Double-U - sorry I could not answer your PM, it did not work