That thought about rust has crossed my mind but we are talking about stainless steel and I think I would be OK regarding any rust issues. There are no leaks in the system and the drone and/or DB's seem to be radiating up from underneath. I can't help but think that the muffler is emitting some of its noise from around the body of the muffler itself. I am going to give it some more thought and get back to my exhaust guy to ask what he thinks as well. I was hoping someone here may have had similar issues and tried something like this to counter act excess unwanted noise or drone. I have had similar systems before so I know to expect noise but this one is a little more than I expected.