Please help I have this annoying rattle coming from the rear passenger side

[5.7_Dario]

This is my video of the rattle. The truck just got returned from the dealership for other things and i told them about this rattle yet they said they couldn’t replicate the noise. I have a 5 hour trip tomorrow and i cant take this thing back in since i need it. Anyone have any idea? The noise is coming from the rear passager area.

 

[Dookie]

I had a similar rattle and upon inspection, I found an 18mm Snap-On brand high angle socket was still sitting on top of an unfinished torquing seat hold-down bolt. I believe it was from the dealership installed Bed LED lighting kit. I used the socket to finish the job they didn't and threw the socket in my box, rattle gone.

 

[5.7_Dario]

Apon further inspection i found the bolt that hold the top of the seatbelt was loose or just missing a washer causing the seatbelt swivel to move excessively. I dont have time to take apart the trim so i put an adhesive to prevent metal on metal contact. I will take it to get it properly checked out after my trip but so far i think I found the issue.