Help with replacing factory speakers and adding an under seat subwoofer and amp

[cds311]

I have a 2021 SX Prestige. I would like to upgrade the factory speakers, possibly the amp, and add a subwoofer under the front seat (both front seats, if possible. But, I know the factory speaker amp is under the passenger seat so that likely can't happen). I am not at all interested in drilling and or adding anything (subwoofer, amp, etc. to the back under the false floor or anywhere else where there aren't already speakers or an amp) to any area that otherwise has speakers (aside from adding an undersea subwoofer). I do know there are a lot of threads about speaker/subwoofer upgrades, which I've spent a few days reading, but none of them meet the needs of how I'm wanting to do this which is why I'm making a new thread. Can anyone help (ideally with pics of what you've done)? Thanks so much!

 

[Maxton]

I replaced the lower door speakers and it didn't really make a big difference. Seems like an amp is really needed to get the most of aftermarket speakers.

This guy upgrades speakers and adds a sub under the passenger seat on a Palisade, which is basically the same car. I followed this guide for the door speakers:
Part 1

Part 2

Part 3