Your best scenario is change the speakers and use an amp... Don't forget the subwoofer... You can get a Full system from us for $799.95 shipped to your door... "370Z Stage 1 system" Complete with Front speakers, Amplifier for fronts and subwoofer, Subwoofer enclosure and a Subwoofer...
If you do not want to get into all that I understand, But it really helps to have the full range of the sound spectrum in your car, reduces the risk of you blowing your doors speakers, because they will not be able to produce the sound you want in the low end by them selves.
Wicked C.A.S.*::*MAGIC BOXES*::*Nissan*::*370Z Corner Stage1 Package. Stereo system JL AUDIO
I can also put together a package for you with just speakers and a 2 channel amp...