My 06 CTS has a bad rattle in the back rear passenger side area. It has been in the shop twice already and they can't seem to find the issue. It only happens on rough roads and and around 30 miles an hour. It sounds like some thing is loose and plastic. Help:(

Have your tech check the hinges on the trunk. My V had a rattle like the one you're talking about. It was the in the front, though. Turned out to be the left hood hinge...after the dash was torn apart.

It could be your Rear clip bumper cover vibrating against the rear right quarter panel make sure that there is no space betweek them and that your clip is fully tightened and against the quarter where they meet.

Is the rattle coming from inside just back corner over the side window area. My car has been in 5 times (also in the shop today) for the rattle.

Is the rattle coming from inside just back corner over the side window area. My car has been in 5 times (also in the shop today) for the rattle.


take out the back seat and see of the rattle goes away .. if not, have someone else drive and you ride there with no seat .. hopefully, you will find the guilty part.


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My dealer seems to think the rattle is coming from the seam in the roof and pillar line. He has photos of the spot and next week will try and fix it. I have had my entire rear section (of my car) removed and put back with insulation. The rear seats have nothing to do with the rattle.