Popping noise from the rear when the car flexes.
- Most noticeable when going over the speed bump or drive way in an angle.
- It's a single "pop" noise when the car flexes. Sometimes another "pop" when the car goes back to flat ground.
- When the rear seats are folded, it stops popping.
Spray some white lithium grease on the metal parts circled in red circles above. I sprayed enough so that the grease covers all around the metal. Top, bottom, back, and front.
I first tried WD-40 and it got rid of the popping noise, but I still could hear some rubbing noise.
I went ahead and bought white lithium grease. The noise is now totally gone.
UPDATE: It might be a better idea to spray white lithium grease on the latch on the rear seat rather than the metal hook in that picture. Grease on the metal hook might dirty the carpet on the rear seat.
UPDATE: Marine grease on the latch on the rear seat worked better than white lithium grease.