Recently while driving over a small bump in the road I would get a thumping sound from the rear drivers side.The car is a 2005 Titanium grey GT with 38 K original miles.All OEM.I put the back on ramps and could see Nothing out of the ordinary.Everything looked great so I used a silicone spray on every joint,bushing etc that I could find.After a drive-NO MORE THUMPING on bumps.My guess was one of the sway bar bushings was dry.Lube! Hope this might help another member! ✌️