I already do this with my HTPC using Media Portal which has a kinnect plug-in. This is pretty cool, but for a carpc? I rather use RRVoice and keep my hands on the wheel. Check this out----------> http://www.youtube.com/watch?v=hbwqEArOQcw
i briefly considered the kinect as a input device as well. the problem is the distance that the device requires-- look at either the video from kinemote, or rawpwr's link, either video shows the user at least 5-10 feet away from the tv. in a car, we would require the device to work with the user in a range of less then 5ft-- something in the 1-2ft range..