The rattle comes mostly from the parcel shelf and other stuff that may be lying in the boot.
I havent noticed any back panel or door cars rattle yet in my car,hopefully there wont be any.
But the parcel shelf is truly a nightmare!
The rear windows in the ep82 do have tendency to rattle a bit and open a bit with vibration.
The parcel shelf can be made to be held tight by inserting a piece of rubber in the supports that are in contact with the boot when it is closed. [using comp at work now,cant access pics,maybe tomorrow i will post pics]
This prevents the parcel shelf from rattling against the boot.