AutoPC ideas

I'm mostly posting this as a place to organize these ideas and get some feedback.

I've been considering how a car would be if I were to try to spec it out to my liking. That said, I would like to be able to have a full computer system with minimal footprint on the car. This computer would need to be able to:

• replace the car's stereo system and use its own audio.
• have a low-power draw, possibly idling while the car is off.
• play media files (MP3, perhaps FLAC) from a hard drive or a USB drive connected.
• be shock-resistant, as it is going to be mounted in a car.
• cost less than $500 for the base configuration. I may add more components or interfaces over time.
• minimize boot time, in order to be functional as quick as possible.

My base configuration for my AutoPC I'm deeming as the following:

1. Base computer for all the heavy lifting.
2. Swappable SATA hard drive.
3. Small keypad, possibly just a modified number pad.
4. LCD text display, for audio file management.
5. Bluetooth audio.
6. AUX-in.
7. Shock-resistant padding.

Eventually, I may add other features to it such as a DVD-ROM drive, touch screen, a more in depth display system for playing DVDs, Bluetooth phone integration, etc. I might also integrate into the car's electronics system for other purposes, such as remote or timed car starting.

For my base computer, I think I'm going to start with something like this NorhTec MicroClient Jr DX. Small, low power draw, provides plenty of connections, no base moving parts, etc. Being able to boot from a MicroSD would allow me to custom fit the software to fit my needs while still having no moving parts. The PS/2 connection would be able to provide a nice standardized interface for a keypad. USB ports could be used for Bluetooth, connecting a phone or a flash drive, or other purposes. Onboard audio provides a place for audio in and audio out, easy modifications to put into the car's audio system. COM ports provide an interface for possibly tapping into the car's electronics system at a later time, and for the LCD character display. Integrated NIC could serve some other purposes in the future.

If the project ever pans out, I'm sure I'll learn more about how to interface with the car's audio system and integrate it into the electronics systems and such.

IMy price list would consist of about the following:

1. NorhTec MicroClient Jr DX - About $200, shipped.
2. MicroSD card - $5 for a low capacity one, or recycle.
3. Bluetooth module - $5 for a cheap one, or recycle.
4. Number keypad - $10 for a basic one, or recycle.
5. LCD display - $30 estimate.
6. Hard drive + USB interface - $70 estimate, or recycle.
7. Car-related connections - $50, since I don't have any real real clue but would give an estimate.
8. Shock-resistant padding - $50, same as above.

Total as of right now: $420.

Any thoughts or feedback would be greatly appreciated in the comments.