Originally Posted by leonkurzweil
Also, I opted to not replace the head unit..although some of the XM ready radios had "outs" for the little subs behind the seats. The best radio was an Alpine I think and the retail was $550 or so, without installation.
Just for your info, the headunits that have the outs for the subwoofers aren't really meant to power the ones behind the seats. In fact they can't power them at all. They are meant to go to an external amplifier to power the subwoofers, which you would have to buy seperately, because aftermarket headunits don't work with the amplifier supplied with the car.