Pictures of filming on Series 5 of DOCTOR WHO have thrown up some interesting points. If you have a closer look at the wreckage it states BYZANTIUM (close up below). Could this be a reference to River Song's comment to The Tenth Doctor, "Crash of the Byzantium, have we done that yet?" (SILENCE IN THE LIBRARY, 2008)
See more pix of filming HERE, HERE, HERE, HERE and HERE.