Well Patrick just got off the phone with Crutchfield, and he said their is no adapter that will let you keep that 6 CD changer. You might want to upgrade speakers and keep the factory head unit. I have the same setup as yours. Mine is 2000, what year is yours. I also was under the assumption that the top Mach Stereo had a separate 4 channel amp for the front 4 door speakers. Well I was wrong, it has a built in one in the head unit, probably no more than 14 watts per channel. Their is a subwoofer amp, so you might be able to boost the bass by using a higher wattage one with a wiring adapter. As far as speakers for the doors, choose a set with a high sensitivity rating, 91 or higher. The factory sub might be able to handle a wattage increase. The factory amp is only around 35-45 watts mono. It's small in size, so if you want to just pop another small one in same spot, with say 60-80 watts, the woofer should handle it as long as you don't overdo it. As far as the speakers take your time, audition a few of the efficient 6x8 ones. Infinity and Jbl come to mind. But everyones ears are different. Hope that helps.
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