Mine is a standard stock exhaust to the cat pipe. From there, I have a Bursch test pipe then a stock 2.5 inch cat back, until it gets to where the muffler is. Instead of a muffler I have a stainless Supertrapp ( with the glass packing ) BUT no end cap.
If you listen to my videos i posted, that sounds nothing like that crap, in that video you posted. It's not a good representation to use a normally aspirated car vs a turbo.
Turbos, have a tendency to be quieter because the exhaust has to go through the turbo hence its quieter than a regular N/A car. My WG dumps back to the cat( test pipe) not the atmosphere

 

I was have a new exhaust fabbed up with a pre muffler dump while they had the "cat back" I drove it for a day open mid pipe. Was very very loud but I deffinitly prefer it with 1 magnaflow still sounds good and isn't intruding on the cabin, I've been told its still very loud outside the car even with the wastegate tied back in.

 

Dougs951 has a straight pipe on his 944 S2 and I'll say this: It sounds glorious at WOT, especially in the upper RPMs for all of about 15 minutes. After that it causes a headache and ringing in the ears. Wisely, he installed an electronic exhaust bypass wired to a spare sunroof switch.

I've given heavy thought to fabricating a boost-actuated exhaust dump where it would start to open at 3psi and be fully open by 7psi. That way I can drive around without being a jackass but still get that tiny performance bump and some sweet sound when I'm out hooning. There are a couple of companies producing weld-in units, only requiring you run a vacuum line to the actuator for somewhere in the neighborhood of $500. In parts alone, it's probably a $150 investment and a few hours of fab time.

 

You'd be giving up the spooling advantage of a free flowing exhaust
A regular cutout would be better

 

here you go.. no cats or mufflers straight pie at 4500rpm turbo S
http://i158.photobucket.com/albums/t91/aussiebj/944%20turbo%20race%20car/20140920_180045_zpsc26de752.mp4