If you pull out the drink holder you can see that there isn’t much room for a sub under there, the shift cables run forward and there is a big metal bracket that houses a large electronic module.
The console will most likely vibrate to high hell if you did manage to squeeze a sub in there any how since it wasn’t designed to have one mounted in it like the Tahoe and Suburban’s do.
I added two 12s to the existing system in my car and it was a piece of cake. All you have to do is buy a converter that takes your regualr speaker cables and changes them to RCAs. Not sure of the actual name cuz i had them in my 03 cts. Afta that all of your connections are in the trunk and you only have to run a remote like to a switch or to a fuse. So simple and really makes the system even louder and bassier if thats a word.