is the wiring for the oem subwoofer in every car? ie under the seat or does the subwoofer attach to the radio directly. if so is the low pass filter built into the head unit or the sub itself.
i am looking for a source for my aftermarket amp, and if there is already a low level imput under the seat then it should be easy.
anyone else running a sub off the factory head unit? where did you get your signal from?