Do you know if I can put a coupe bumper and exhaust on a sedan by any chance?
I always liked the traditional dual exhaust on my sedan so I never investigated this, but based on what I can tell, this would be pretty difficult to accomplish.
With enough money anything can be accomplished, but I believe you'd run into issues with both the bumper covers and the exhaust. If you google cts-v exhaust images you'll see some under car shots that highlight the differences in the exhaust routing between the sedan and coupe. The sedan has the spare tire well (no spare tire, but the well is still there) in the center that would likely make it challenging to route the exhaust out the center.
Best I can tell there is no off the shelf solution, it would have to be custom ($$$).