Here is a tip for you guys that want to hear the engine but not anoï the neighbours:
As I am working on my Magnum's intake baffle installing a Catch Can, I have temporarily made myself a makeshift CAI with some dust collection 4" tube. Because this tubing is very thin walled, the noise coming out of the TB is great and envelops the cabin between 2500~3000 rpm, but the outside noise is not changed at all.
For my wife's sake I will be putting the baffle back on the truck, but I do enjoy the sound currently, really does sound like a Muscle car even though it is only a 4.7.
My current setup cost about 15$ and can be adapted for pretty much any engine. If it ever raises interest I can post some pics and how to's but it is a very easy and low cost mod. Not sure it brings any HP gain as some real CAI can, but the sound is just great.