I was looking at just replacing the factory subwoofer and using the stock enclosure. I know there usually is not a huge difference in doing this. But in my past vehicles it always helped get a little better low end and sometimes a tad louder. (that depends on the efficiency\sensitivity of the woofer though) I have found conflicting reports that is a DVC 4ohm and another post say it is a DVC 3 OHM(Which would be impossible to find). Also if any one has done this what sub did you use? Any benefit to poly filling the stock enclosure?