I did look around but there's not much info for Sedans.

Have an 03 Sedan - premium Bose.

Want to get better base - not "earth shattering" but more "heart pounding" i.e. i don't want to wake up the neighbours but do want to get a deep good quality bass for listening pleasure. 80's pop and rock is what i mostly listen to.

If i could improve the overall sound quality, it would be a bonus.

I know some would suggest replacing the HU/Speakers but I don't want to make any drastic changes to the car so the changes have to be minor and reversible. And i would like to be able to do it myself.

Can spend a few hundred $.

Need advice on -

1. What to get.
2. Where to get it.
3. Where to put it
4. How to hook it up.

Please assume i am the extreme noob.

Thx.