One of the main factors of the 04 was "time to market".. right? Didn't they go from Aussi to USA in just a few months?

And yes the current exhaust is true dual..just exits from one side..there is a really good picture of the underside of the car on pontiac.com or this link

http://www.pontiac.com/gto/gallery.jsp?brand=gto&pagename=models_prices

It is the next to the last picture.just click the thumbnail.
from the looks of that picture they are gonna have to change something to get dual outlets.