Got a question. I'm thinking about Kicker KX 400.1 with the Kicker S10 L5, but I really don't want to remove my stock deck (at least not yet). So can I hook up the stock 2003 GT deck to the amp and then the amp to the sub?
Yes, you just need to get a line out converter. You can get it at just about any car audio shop. You just connect it to your rear speaker wires behind your stock deck, then just run your rcas from the converter to you amp.