I have read about other years about replacing the deck but not 03,04. I think they use the same wiring adapter but according to metra it doesnt say anything about mine. what I think I am going to do is install my Alpine 9835 setting the internal crossover to active and wiring the front tweeters and subs to the deck power and crossing them over with the deck. Running the sub output from the deck to the rear subs and having control of them from the deck. One thing I know about the Mach system is its missing the midrange. All it does is run tweeters and subs. I am hoping by doing what I am going to do it will sound better and be more full. Anyone ever do this?