Well I've been going back and forth with what I was going to do with the stereo in my g35 and I finally made up my mind. I'm putting a elemental designs sq10 subwoofer in a fiberglass enclosure in my spare tire hooked up to a mtx amp thats coming in the mail. I going to use the speaker level inputs on the amp (not thrilled about that) hooked up to the back speakers. I don't want to change out the headunit because it costs like $350 for dash parts I need from japan and I would have to get a double din because the single looks really bad in that car. The amp comes with a remote bass knob so I'm going to mount that in the ash tray cubby. I have the spare tire all taped up and I'm going to do the fiberglassing tomorrow after work. I'll post up some pics as I progress. 
Plus in the 05's and up they added real brushed aluminum dash pieces which is really plastic with a real thin gauge steel bent over the plastic.
