Here's my little project. I've put a mac mini in my 2006 Jeep Wrangler. I'm using a Xenarc touchscreen monitor, a 450 watt inverter. I'm routing the audio through my Pioneer head unit that has an AUX port on the front. I've yet to put the usb GPS unit I have because I need a USB extender. I have loaded it on the Mac so I know it works. Here are a couple of pictures.
Here are a couple video's playing with my Mac Mini and explaining the front end I'm using.
Showing off Neon Boombox front end. I like this front end shows alot of promise on the Mac end.
Explaining how I get Sirius through the Mac Mini.