Ok, a few things here....

Kiko, that video is exactly the sound I have/had. Identical. LIke I said, I've quieted it down, or 'dirtied' it. But the sound is identical.

Bulldogger suggested its the supercharger backing plate. The video he posted was from a forum member here who ended up solving it by showing us the backing plate to his s/c pulley was loose. I don't have a sound as major as that s/c video, and neither do you kiko, but I can confirm that my backing plate on my s/c pulley does have play in it. I can flex it with my finger pushing it. After receiving my Code3 pulley and inspecting it today I can see that these backing plates probably shouldnt flex or move at all. So Kiko, its possible we have the same pulley problems as Bulldog's video, just not as pronounced yet.

Or, we have a different problem. I can't deny that our sound is definately coming towards the corner nearest the driver, but a supercharger pulley problem can bounce its sounds anywhere. I hope my belt, idler pulley and code3 install will solve the problem, and if not then it will rule out the belt system as our problem.

But like I said, your vid clip is identical to my sound. Audible loudly under the car, but if you stethescope the oil pan you don't hear it. If you stethescope the top manifold or cylinders, you do hear it. And you hear it in the driver's cat. You do not hear it in the passenger cat.

And then theres that fact that you can't even put your hand behind the engine after driving because the hot air alone will burn you.

I'm still leaning towards us having a dead driver's side cat, but this weekend's belt system changes will help rule that out, or make it even more likely.