9600.... The bottom of your shifter sits right above the midpipe and right next to some heat shields. One could be loose and hitting up against the shifter. does it still make that noise when the car is off?? I can find some pics if you really need some.

 

when you look under the car you will be able to tell. the exhaust will be free and nothing touching or rubbing up against it. the heat shield that made mine rattle like a SOB was right past the cat. the cat is covered in plates, but those weren't my problem. mine was the shiel right before the shifter. it some how got bent up and was sitting on the midpipe, causing an awful rattle at low rpm's.

 

hey thx guys gonna check it out when i figure out a way to jack up the car.

 

I'll second the above. You must not have the proper speakers.