very well man that sub is excelent and his enclosure is qlogic, thats what RFs recomends to use... im thinking of buying now a dvd player or another sub...
Your system looks pretty good. Not bad for a start. If you buy good set of 4 inch for the front, use them for fill in sound not for power. I had a Ford Festiva a few years ago and I had 4 inch speakers in the front factory speaker holes, the back seat factory speaker holes, and two 6 inch subs in the back hatch. The sound was pretty good for a little car. It kept me happy for many miles.