Maintaining the center exhaust isn't a problem with aftermarket systems. I dropped an UPR O/R X-Pipe on mine with some Flowmasters (just changed back to Magnaflow), welded the center exhaust back to the backs of the mufflers, and have the actual exhaust dropping down right out of the mufflers. It loooks totally stock and since I have gone back to Magnaflows, my car sounds like it has way more CI's than 281.
Regarding the sound, don't go with Flowmaster Mufflers as they will make your car sound like a sport bike w/ headers. I did that and it drove me nuts with an O/R X-Pipe. A guy around here dropped some JBA Ceramic Long Tube Headers, H-Pipe, and JBA Hi-Flow Cats onto his car while maintaining the stock mufflers (Magnaflow) and utilizing the center exhaust and his car sounds absolutely menacing - kinda' like a NASCAR.