be careful with the w7 because one of the most important things about the sub is the box you put it in. make sure it comes with the pre-fab box that jl made for it, otherwise it will sound like ass. make sure you have a really good amp attached to it, and don't get a class d (no matter what brand), because class d amps suck. go for a class a like a zapco, i'm running a 500 watt (538 watt rms) zapco amp with my eclipse aluminum sub in an enclosed box, and it hits hardcore. just be sure to get good speakers too, otherwise the system will be lopsided (hatchback as opposed to sedan or coupe).