BMW E46 Sedan Audio set up.

Hi Fanatics

Can you guys please tell me how do you set up your audio inside your sedans.

I currently has a aftermarket bluetooth headunit with aftermarket co axials speakers 2 fronts on headunit and 2 rears on the deck on amp. Also an 12inch sub running with the rear co axials on the amp. 4 channel 5000w amp.

I am happy with my bass but wants more from my speakers.(do you guys run it all from the head or amp.)

I just wants to know how you guys set up your speakers and do you run it from your headunit or amp.

Thanks