Don't know what to tell you. I have 8-year old Mac shorties and the single flange issue did make reinstallation a PITA, although I was ultimately able to bend the tubes to match the ports. Mine came with the base nickel-whatever shiny coating, and it rinsed right off with an application of foamy engine brite, so that's two points against the Macs. On the other hand I have a BBK 2.5 cat h-pipe that fit like crap, BBK didn't care much when I spoke to them about it, and it ticked me off so much I swore I'd never buy BBK again.
