I had this issue for the past 12 months it started off happening randomly then as time went on it happened more frequently. My fix for the issue was to unhook the power plug to the rear glass lock. To do this requires removing the inner rear tailgate panel. This makes the rear glass inoperable but we never used it anyway. When driving you can hear a faint click sound every now and then coming from the left side of the vehicle in the luggage area but no more open window. The process took 15 minutes to do so fairly simple.
