Originally Posted by MrHarris
I'm 95% sure my exhaust is not touching the heatshield, cold or hot.
It doesn't have to be touching it buddy. Remember resonance rattle things not even close to your car
I suggest you put your car on ramps, start it one morning (when it's the roughest), and get on your back right away to investigate. If the heatshield doesn't have a healthy gap from other panels, that can be your problem. I agree the strap is not going to rattle much; just make sure it's not coiled or touching anything. Push the heatshield lightly with your fingers all over, and if it touches anything, pull it a little bit to create a bigger gap. Good luck, and hope you find the culprit. Keep us posted.