Wow, no one's responded. I don't know if I've an answer for you, Xzellerate. Right now, from what I can see almost all the forthcoming mods are for the coupe and especially the six speed manual. About all I see out there is a Stillen (stillen.com and other e-tailers sell his stuff cheaper than he does) rear muffler only for the sedan. However, now that the manual trans sedan is out, there could be more exhaust mods for the sedans. I just saw a sedan run at practice for SCCA solo two this afternoon; nice car.
My take? I'd go to i-m-racing.com and call them and ask for what's out there for your sedan. I'm with you on sounds; I'll be taking delivery of a coupe very soon, and I'm not into loud exhausts that drown out the engine or music. Plus, noise gets very tiring especially on long trips which I do quite a bit.
That's why, whatever you buy, try really hard to go hear someone with it already on. When I was looking at a possible purchase of an Acura cl, I found a guy thru an Acura dealer who let me drive and listen to his mods. They were too loud for me. At the moment, i've got Borla rear mufflers only (not catbacks) on another make of car. A friend has a full catback borla system and if I'd put that on, I would have gone nuts [

!] listening to it. Mine is mellow and can growl a little [

] when I floor it; his is loud-loud all the time and really loud when he floors it. Nice if you're going drag racing all the time, but not for me.
That's all I know for now. Good luck and keep drivin'!
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