The system I installed about 5 years ago in my contour was around $2300 and included a Sony Mobile ES cass head unit,Sony 10disc changer,Sony DSP unit w/eq,a Sony crossover unit,two 8" kicker subs,a kicker amp for them,a Alpine 6ch amp(sucks,won't ever buy another one for sure...)Polk 2 ways 6 1/2' in front door w/directional tweets aimed up and dats it. I never did get fill in the rear doors....too friggin difficult running the wires and I burnt out doing all that myself. Running the wires front to rear was a pain in the .... and my amps I mounted to the trunk carpet using tie wraps,and had to make my own adaptor for the subs which are mounted under the rear deck w/ wood adaptors. That was a pain in the ....too. The head unit is in need of upgrading now,but am looking for MP3 type units. Getting away from cassette and would like CD w/MP3 capability on CD R's,and also ditching the changer and going MP3 jukebox type for that also. Still waiting and watching for the most versatile in home/car unit out there. Anyone know of any??? With a large capacity,holding 100 or better albums and can be hooked to the home unit.