ok follow me. if you wanna slap you need a 4 channel amp with about 100 watts per channel for inside speakers. the good guys can install this under your seat, set it up to push your speakers properly and you will have a quality sound inside you load.
but now comes the real shit. you need a rockford punch 2 chanel amp watts depends on your speakers and get you a box with some 12 inch jl audio speakers in it and have that installed and you will knock tremdo.
or you can just run your shit off your deck. 4x 50 watts is 4 chanel power enough for 4 speakers inside the car off the deck so you straight. the more amps and speakers you got, the more you knock.
good luck.
breathe.