I just purchased my tC last week. It has yet to have a radio installed because the technition had left for the day by the time my car was ready (I guess they don't install radios right away incase the buyer wants to upgrade). My question is about the sub. I have at home a powered bazooka tube sub (EL6A-HP) that I wanted to put into the car. A couple of posts discussed a wiring harness toyota sells for the subwoofer option that plugs into the back of the head unit. Can I use this harness to power my sub or is it only for non-powered subs? Any information will help.