You can actually use a amd am3 processor, with a mini itx main board.
A 128GB SSD harddrive, 8 GB DDR3 ram, and a good creative sound card and kX project audigy/EMU drivers.An enclosure may be a problem, but you can check the site mp3 car for more info. Once you have your pc constructed, with your dc to dc adaptor, you can power it on.
After you can install Windows 7 and choose either winamp, foobar, with a host of different out plugins but the kX drivers allows you to tweak the sound to your liking.
If you feel like dj'ing from your car pc you can install virtual dj.
Hope this helps
http://www.kvraudio.com/product/vst_hos ... tian_buddeVST plugins for winamp
http://www.kxproject.com/shots.php?language=enEffects available :-
Reverb Lite, Stereo Chorus, Delay, Overdrive, M4Tube (TubeSound), Chorus, AutoWah, CL Reverb, ProLogica, RingMod, Eq10a, APS Flanger, APS AutoWah, Stereo/Mono Vocoders, Overdrive2, Encode4, APS Fuzz, Stereo Mix, Mono Mix, Pan, Pan x2, EQ Bandpass, EQ Highpass, EQ Highshelf, EQ Lowpass, EQ Lowshelf, EQ Notch, EQ Peaking, Frequency Splitter, Stereo Volume, Downmix, Cnv51To2 (kXSurround), APS Compressor, B2B, ac3passthru, Phat EQ Mono, Phat EQ Stereo, WaveGen, Everb, Surrounder, Gain, Decimator, Crossfade, APS Pitch, CLEAX3Reverb, FXMix, Epilog Lite, Prolog Lite, FXBusX, APS Compressor+, FXMix2, HpSp, MX6, Expander, Expander+, WaveGen3, DelayA, DelayB, Dynamics Processor, NoiseGate2T, NoiseGate2Ts, Vibrato, 2nd-order and 4-order Crossovers, BoobleGum and Timbre - included with the latest kX Driver package or bundled with kX FX Pack add-on