I'm looking for the one that is upstream from the resonator. I'd like to remove the resonator and figured mating to the existing flange would make for a cleaner install. I would prefer to leave the existing flange attached to the resonator, just in case I ever wanted to put it back. It looks like the side that I want to replace is threaded for the two bolts. The flanges I've found online require a nut and bolt. So is it possible to buy the OEM style flanges? I suspect Volvo only sells them as part of the whole exhaust or at least as part of the resonator.