it's not rust...SS changes colors when heated up, and the x-pipe and the ends of the mufflers get the hottest...i've got a sale pending to a guy on NLOC, but i'll let u know if it falls through
I'm SS Bassani is 2 mons old and looks just like this unit. I live in Arizona where it is very dry. The discoloration surprised me as well when I first noticed it. A mechanic told me it was heated related. I paid $700 new shipped from LFP, so this is a great buy at 6mons old.