I recently had a borla muffler swaps in the stock location leaving both Flappers in. I'm glad I did because I can still hear the faintest hint of the strange tone when cruising at low speed and active fuel management kicks in. Over all time very happy with the sound nice deep sound when you get on it but you really can't hear anything when you cruising on the highway.
I did not want a constant obnoxious sound just wanted to be able to hear the v8 I paid up for.