I don't have a 9-5 but on my 2.0 9-3ss Aeros (both of them) I had a Jetex cat back system. That was very nice sounding, with crackles on the overrun at times, although I didn't quite get the fit right on my 2007 car when transferring it over (it always stuck out too far).
On my 2.8 9-3 Turbo X I have had a custom stainless partial system made from the "rumble box" back. This removed the rumble box for a Y piece and means that the system has only got 2 new rearmost silencers. That one is loud enough to set off car alarms if people have left their window open a crack in the heat and burbles very nicely. However, on the road it doesn't drone too much and it sounds great if you open it up. The fabricator was Fast Fit Service Centre in Basingstoke. They offer Longlife work via franchise but are actually a business in their own right and well regarded for exhaust work. The FastFit name is a bit misleading as that is just part of their work!
I have therefore determined that Jetex systems are to my taste and that research before selecting a custom stainless system is important.
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