you need to remove the back seat with a few bolts, but first you need to remove the bottom half of the seat by pushing downwards then clicking them out, undo the screw clips, remove the centre brake light then itll come out.
I really wish I had realized it was that simple about 1 year ago. from looking at it it looked like the above mentioned + the "C" pillar covers. In an attenpt to remove these I have managed to break the plastic strip that runs across the top of the rear window. Was this an easy to remove part or did they just glue them all on to the retining clips and on tothe roof trimming?