I have been working diligently with others over at awkwardtv to get linux running on the appletv for mythtv. We have this working pretty well and it got me thinking about replacing my carpc with an appletv.

Linux ICE distro looks like an interesting start, and I found this DC power supply mod for replacing the existing AC power with DC for car use.

http://mikegyver.com/IdeasnProducts/AppleTV/index.html

He is currently waiting to gauge interest before he goes to production with these, so if you are interested go to the site and pre-order so he will know its worth building.

Beyond that, I'm just curious, how many people would be interested in me working on this as a project? By that I mean, get a good working linux-ice install with the DC power and upgraded hard drive and provide them pre-built and/or instructions for DIY.