I just had a new exhaust put on 2 weeks ago at my dealer. I wasn't planning on having it installed that day and I just happened to ask the parts manager what he thought of Corsa Touring and he said that he's had several people bring their cars back due to a backfire problem, (even with a X Pipe installed).
He showed me a Chevy approved high performance exhaust in his GM catalog which he said sounds better with no pop-pop sound like Corsa has. Anyway I had it installed and it sounds great, just like a muscle car shood; in 4th gear it's very subdued. It's louder than a Z06 and has 4 chrome tips. Check it out. It was $1030.00 for the exhaust system and $310.00 for the Tip pkg. & $13.20 for misc. hardware, cleaners and chemical waste. Total came to $1581.61.
The part number is 19154780 Muff PKG and a 17801886 Exhaust tip pkg.
I also had a Donaldson Black Wing cold air intake installed; that was $497.06 installed.
I haven't had it dynoed yet but I should be getting about 25 more horse from the exhaust and 10-18 from the intake.