Just bought an '05 STi, (woohoo!) and I know that there's an option for a subwoofer under the passenger seat. I didn't buy it because I have a nice JL W6 and Excelon amp to drive it that I plan to mount in the trunk. My question is, where is the pre-amp level output that the dealer would have connected to the otional factory sub? Or would they just split off of a speaker level out and use some kind of speaker to line-level adapter?