What is that bracket for? It's in picture 2 and 3, not in picture 1.
Engages with the round rod /prop rod and holds the trap door in the up position
Owner of car in picture #1 possibly added the fold down option and forgot to include the retainer. (Notice no nutserts in the trunk hinge bracket
Sure they wonder why the trap door doesn't stay up like others cars but then the vast majority of time the trap door is down and maybe never noticed it missing