i have a 99 mustang cobra with the mark2a rio car 30gig version. two rockford punch subs(100w) parallel wired to rockford power 360a2 amp. 4 mb quart 5x7's in the factory mounting spots. the thing that makes the big difference is that i removed my backseat, carpetted it up with the sub box made to fit the angle and it fits slush and hits loud as higher end subs. since it's so close to my ears . i listen to mostly rap/r&b