I seen a few guys that have had luck with www.fireballcoatings.com coating their exhaust manifolds,(approx $250 pr).....I was thinking of giving them a shot, because I tried various forms of "natural" looking coatings over the years, only to have them waste away after hours/days/months/years.......I know rust is the prefered original look, but I prefer a clean raw cast look myself .......I have gone the clear powdercoated route on aluminum intake and cast iron exhaust manifolds, it turns brown with gas or high heat....