I did a quick search after the previous post and found this info. I'm not worried about surface rust under the car where I can't even see it! I was expecting the exhaust today but I think this polar vortex may have slowed FedEx a little bit. I'm in Miami, coldest we've had all "winter" is 45 lolT409 stainless will develop surface rust in a more harsh climate, but that will not effect the longevity or performance of the product. The tips are T304 polished stainless, so they will stay shiny as long as you clean them. Thanks.