2013 3.6R with the 5EAT, I've just started to notice a rattle on deceleration, most noticeable from about 60km/h to 20.
Put on the hoist and with wheels off the ground, noise is still VERY present with no road noise.
Used the chassis ears and verified no wheel bearings or axle noises.
This all started after I replaced the stock battery.
About 2 months ago I finally replaced the stock battery. I went with a Duralast Gold as it was really the only option in AutoZone. I was told it has a higher cold crank amp's than the stock so I figured that was a good idea.