Some great knowledge on this thread. I appreciate everyone sharing their knowledge and experiences here.
Someone was asking about where the stock amp was and how to get to it. This guy made a Youtube video showing how to remove the side panel and gain access for those that are interested...https://www.youtube.com/watch?v=06x14DpMGak&t=11s
However, I think 
@TravisF and 
@Timelessvance have the best solution for those of us that feel the bass is underwhelming.
I love the simplicity of getting that added bass without all the need for custom enclosure and taking up space in the trunk. Yes, perhaps it takes up more space than the custom fab box on the side of the trunk, but then it seems it would be a heck of a lot easier to simply detach the cables, remove the box and then use the trunk for those days that you need it.
Many moons ago, I was super into this stuff. Here are some photos of the custom trunk enclosure I built using the spare tire space in my Honda Accord. I'm not in college anymore and I got kids, so I need to use the trunk as a trunk. 
 
But I have been out of the game a bit. I'm trying to decide between the Rockford Fosgate Punch P300-12 and the rockford fosgate p500-12p, which have both been recommended on this thread. One of them appears sealed whereas the other is ported. One being 300 watt vs 500 watt.
What would be the difference between these two (other than the $$$ spent). Looking for some advice / knowledge on this, so I can make the decision. Thanks!