Ok here goes but don't laugh.
Temp fix to my problem with the rear window and lock to stop it rattling was:
1. Get a hankerchief and fold it in half.
2. Open the window so that it flips up.
3. While the door is still closed place the hankercheif on the lock.
4.Now pull the window down and close it so that the hankerchief is in between the glass window and the door.
I went for a drive and presto the rattle stoped. The hankercheif absorbed the rattle and no more sound.
Long term fix was I drove the KJ to Jeep with the above set up and they changed the entire lock after they had a good laugh