I have a 2007 9-3 Aero convertible and have seen there is space between the back seats for a 10 inch subwoofer cone.
I read the the connection is possibly slightly easier on the 2007+ models but when I took apart the boot lining I couldn't tell where things should be plugged in. I don't really know anything about this but just know I need power to a new amp and a signal in.
I've attached a photo of the amp and fuse area.
Can anyone give me any advice or point me in the right direction?