I once was going for sound...
6 10'' competition sound streams... powered by to alpine v12 amps... boy was that loud!! it bent my two rear doors outward!
since then i downgraded and am now geared toward performance... but i'm a sound junkie
Kenwood Mask (tape)
6 disc changer
pioneer 250 watt components in the front
phoenix gold speakers in the rear deck
2 12'' PPI's
Sony, and alpine amps...
What i've learned while doing all this is that wiring is what counts... I've been wiring my car and rewiring it for years just to squeeze more power out!!
A friend of mine actually got his professionally installed... got 135db... i rewired it for him with proper wires (1guage) and rca's and he hit a 145db!!!