imyy4u

OK, so I have only 42,000 miles on my 2006 Mustang GT 5-speed. I have had the rear end moan-groan TSB done twice, and have had other engine rattling/noise problems fixed such as that one with the rattling engine plate. However, there is now a loud rattle that I can't seem to get rid of, which became noticeable after installing my SLP loudmouth exhaust a year ago and it's making my car sound like a piece of junk.

Upon deceleration, and sometimes on acceleration, the back of the inside of the car (where the rear speakers are mounted, behind the back seat) rattles like crazy at certain RPMs. Not to mention the whole car squeaks like crazy when I go over bumps. I have checked the exhaust, engine, drivetrain, etc., and have determined it is not a mechanical issue - but rather that little area under the rear window behind the back seats that is rattling. Has anyone else had this issue, and if so, how have you resolved it? I am quite annoyed that after 40,000 miles my car is already rattling like this - what kind of shoddy workmanship/design is this? I have been in imports with 200,000 miles that rattle far less than my car.