It probably would, but it looks like a lot more work than I would want to undertake.
I had a word with Ian at Saabtech yesterday, who knows my particular car like the back of his hands since he helped to assemble it from the SAAB parts bin. He pointed out that the NG900 twin exhaust for the 2.3 litre engine, as fitted in my 9-3, runs in a different configuration. So the pipes won't fit.
What I do regret though is that I had no idea that SAAB made a twin pipe exhaust for the 2.3 NG900. I had one of those before and would have loved to have kitted it out with a twin pipe exhaust.