Toyota Tacoma 2020 Rattle Noise (Backside)

Hi guys,

Hope everyone is doing well. My Tacoma has develop a rattling/grinding noise which seems to be coming from the back side of the truck. Noise start right around 40 mph. I've checked the bed bolts, spare tire chain with no success. My truck is stock, no pulling, just normal commute. See link. Thanks for the help!

Link

 

Factory oem bed cover. Bang your hand on cover. Molded in the cover, there is aluminum square tubes. Those are most likely what is rattling. Had that on mine, before I got rid of that cover. I ran selftappers on underside to stopp rattling.

 

Op didn't mention a bed cover. I know the rear of the truck was the complaint for the rattle noise, but those heat shields on the cats are notorious for that.