On this forum we commonly are asked about how to make the 3800 sound nice. The usual answer is that the exhaust alone cannot achieve this as a cam or turbo is needed. Then there is the guy who keeps confusing the term "nice" with "loud." Since the sound is doomed, the best bet would be to lower the volume. Flow would still be an area of interest as this would be for performance as well. This brings me to main question.
What would be the best flowing and quietest exhaust for our cars and why?
More emphasis on the why as I would like to learn about the science behind it.