I just got off the phone with a tech at Gibson, and I told him about the rusting problems some people are having with their stainless steel exhaust systems. He told me that the pipes are made of "409" stainless which has metal flake in it so when they bend the pipe it will not crack. The muffler itself is made of "304" stainless. As for the rust, what you see is the metal flake itself oxidizing, and it is only surface rust (he recommended using an SOS pad to remove the rust if I wanted to). He also reasured me that ALL the parts have a lifetime rust-through warranty, and would be replaced no questions asked. I feel better now.