strange noises

I have a 2000 ss M6, i ve had it since december but within the last month or so ive been hearing what sounds like a heat shield vibrating at 1500 and 2000 rpm when driving. the noise is up in the engine area. when i come to a stop and listen it sounds like something banging around underneath then goes away after a few seconds, increase revs or clutch in/ out doesnt make a difference. ive put it in the air moved shields checked brake lines, nothin changes, nothin obvious. any help?? thanks.

my y pipe hits the bottom of my car when i get on it so maybe

right before my tips connect to the exhaust i could see it making noise because its so close any movement it touches check ur clearences around ur exhaust or it could be somthin else

Ill see what I can find, thanks guys.