Are the roll pins in place? They are located on the shaft, near the rubber boot, where the power shaft goes into the interior of the hatch?
You should check for water under the foam inserts where the jack and air pump are located. If you have water in there you have a problem which must be corrected immediately . First remove the jack and air pump you can see into the lower area there and insert a piece of cardboard forward. If it comes back wet the mounting of your wing has lost it's seal. On the right side of the car under the foam your vacuum pump is located that operates the door lock. That water must be removed and prevented to reoccur, or you will have much more trouble to correct.
You say you inspected and found the "wing mounting bolts are tight". That is not clear in my mine. Are you talking about the bolts you see when the wing is up? I ask because, there are at least a dozen bolts that hold the entire wing assembly in place and those bolts can only be accessed by removing the interior plastic trim from the bottom/interior of the hatch. The motor is also mounted from the bottom and I suspect the rattle is coming from something loose from the interior side.