I just spotted this subwoofer on Crutchfield. You can get the loaded or unloaded version of the enclosure. My question....do I have to by an amp to drive this thing or can I tap into the 500 system somewhere to power it? I previously mentioned I do plan on upgrading the head unit at a later date so expandability is the key here. I don't know how difficult this would be for a do it yourself project but I'm willing to try.

 

Need an amp. I have the unloaded one with an older SoundStream Exact woofer in it.

 

I have the unloaded one also, with an Infinity Kappa Perfect DVC installed and powered by a single channel amp 410w @ 1 ohm. It is a good enclosure. Not too difficult to install - you can tap into the rear deck speakers for the source and run the power line up the pasenger side to the battery. Here's a picture of mine and a second with the amps (second amp is for the door subs) shown.

 

Need an amp. I bought this box unloaded and installed an Infinity Kappa Perfect 12" DVC sub as well.
Driving it with an Alpine MRP-M650 @ 2 ohms.

My trunk looks like this.
Attachment 27893