Since a few weeks ago I noticed this rattle sound near or under the rear seat while in idle. It sounds like the seat or something is loose. I don't hear it in while driving. Any suggestions?

I am taking the car in to the dealer to check it out under warranty.

 

I have this same noise in our 2013 diesel. I don't know what it is, we brought it in once and they got it to go away but it just came back about a month ago.

 

Believe it or not, the dealer said it was the fuel pump. I hope to get the car back tomorrow and will see if that was indeed the cause of the rattle sound.