And well you might ask.

With the myriad of options already available, both fully commercial solutions (such as MP3 playing headunits from established vendors like Sony) and the less multi-national options (such the [apparently discontinued - I feel old] empeg) whyspend time, money and effort on yet another homebrew solution?

Who knows. I don't. Fun, interest, just because. And, of course, because no-one ever does it quite right. Or didn't when the project was conceived. Many years have passed since that day, as I moved through university, part time work and being single, and progress slowed. Interestingly the project is still as viable as it was then, perhaps more so with the drop in prices and increase in functionality of laptops.

Any in car mp3 player needs to be functional - not only easy to use, but featureful. Also, ideally, flexible and not locked into the original design. It needs to be easily updatable both in software and, more importantly, track-listing. Thus it also needs to be expandable (my mp3 collection started at 2Gb and now tops 20Gb) without requiring an entire replacement.

Which leads us to "What?"...