I kinda got all figured out how I am goin to do my Car PC in my 98 SC300. I'm goin to have a HD tuner and a Laptop. The tuner and laptop will have output sound into the car speakers. Now the problem is that the amp for the sub, it is a separate and different plug (stock) from the speakers. How am I goin to wire from my car pc to sub amp to match the music whenever it needs the sub.