The base of this project is a SmartQ5 which will be installed at the double-DIN place in the Saab 9-5:s dash. It will be a somewhat easy project as the SmartQ5 is a complete Arm-based computer in a tiny little package with a built-in touch screen.
The project har just begun, right now I'm testing the hardware and software at home.
The SmartQ is running the native Ubuntu Arm-port, and the main target is to let the device play music. MPD comes installed, the main work here is to create a fingertouch friendly MPD-interface to control the playing. And that's almost finished, a client written in Python/wxPython is almost ready for some serious testing.
The audio comes out of the SmartQ in a standard 3,5 millimeters jack, which will be connected to the car stereos line input. This stereo will be put away in the glove apartement and controlled by steering wheel buttons, and will provide volume control and radio.
For powering the SmartQ some kind of premade carcharger will be used. Haven't found one especially made for the Q, but it seems like one for a TomTom GPS will provide enough power for a good low price.
The Q's starting when the power connector is attached, so power up is no problem. I'm right now working on a solution for auto-powerdown, thinking to use the systems ACPI-information.