Yeah, I have that ish too...the only thing is that they spent like $1200 on theirs... something not too many of us have to put into this thing. They also used parts from suppliers well known to this board, like powersupply from arise computers and a Matrix Orbital VFD display from linux central.
The best thing about it is that it seems to be becoming more and more mainstream to have MP3s/computers in cars, Which means it's only a matter of time till companies like Pioneer, Clarion and Sony start making commercial systems. Anyway that was my impression of the whole thing. The article has already been put online and can be found at
www.maximumpc.com/route66
Enjoy!