I'm firmly in the melted tarp(or plastic bag or some such) camp.
Ya see, a few years back I too had a very similar pattern become "powder-coated" upon one of my headers after a loose grocery baggie flew across the road I was riding down and found its way upon the front of my BA. And afterward, the melted plastic also seemed to be "gouged" upon the headers.
Once the bike cooled, it took me a good half hour to get it all off by using Blue-Away, some 2000 grit wet-sand sandpaper and elbow-grease.
And, due to the classic Triumph twin exhaust design which our bikes have(what with their "spaded out" headers), I know I'm not the only one around here who has needed to do this over the years.
