[Mim]

There is no factory sub, just the front door speakers, tweeters in the corners of the dash and some shity 3" side wall units in the back. I went the path of installing a compact 4 channel amp, replaced all the speakers (upgrading rears to 5.25) and got a new head unit. There is some bass, but its no where near as deep as having a proper sub and enclosure. That said it sounds pretty good to me.

Loads of people go for the OEM+ system that adds a small sub with custom molded enclosure in the boot that has its own amp I believe.

Then there's the option to add sound deadening in the doors and boot. Car audio is a very deep rabbit hole. Our car is limited in options due to its compact nature, but I found switching to higher quality speakers, adding an amp and swapping the head unit kept any weight gain to a minimum and decided to keep what little boot space there was by forgoing the sub.

Bare in mind our car has virtually zero sound deadening so you would likely need to add some if going for decent bass. Trade off is going to be a fairy noticeable amount of added weight.