Mazda has opened the Build and Buy feature on the Mazda3's website, and also put the car on their main car list on the MazdaUSA site. Go check it out -- www.mazda3.com
EDIT: XREF thread: http://mazda3forums.com/viewtopic.php?t=845
EDIT: XREF thread: http://mazda3forums.com/viewtopic.php?t=845