Everything is stock except your Subs and Amp? Thats your problem.Anything can be loud it just won't sound good.
Whats your Budget?
Amperage rating of your Alternator? Normal Non-Audio Amperage Load?
Battery Size?
Sub/Sub Amp Brand? How are they Wired? Whats there Amp Load on your Car?
First you need to know your cars electrical system capacity and then work with that and your budget. If you put amps and speakers that are too powerful your car will never sound good unless you upgrade your electrical system which is big $$$.
When you work that out, we can look at speakers, amps and different installation techniques.