Dimension stereo upgrade options?

Hi All,

I'm the new owner of a 2012 CPO Azera with the base Dimension stereo.

I'd like to understand what it's pieces are in case I want to upgrade it, in particular the speakers.

I gave Crutchfield a call, and they had info on the dimension, but not the Infinity. They said that the Dimension system is 2-ohm, not 4, which may limit some choices.

Can anyone help me with the following?:

Any idea of how many channels the amp has? It may need to be replaced as well. Crutchfield suggested 5 channel.

Is the head unit the same with the Dimension and Infinity, with the difference being the amps and speakers?

Can anyone verify what the speaker layout is?

The front seems to have midrange speakers in the doors, with a pair of tweeter on top of the dash, and a center speaker on the dash. Is that a 2-way component left/right with some kind of center channel taking both l/r signals up front?

The rear doors seem to have midrange speakers in the doors, and the rear deck has a large speaker performing as a subwoofer with 2 tweeters as well.
is that another pair of l/r 2-way components and a center/sub?

Any help appreciated. From what I'm hearing from it, a speaker swap may make a big difference on this system.

Thanks