I spend a lot of time in the my Jeep (2004 Grand Cherokee) and I normally either listen to NPR, Podcasts or Pandora while driving. I wanted a way to interface Pandora directly to my Jeep without spending a bunch of money. After researching I devised a plan that would get me what I wanted for about $200, a fraction of the $400+ dollar units.
I already had a Raspberry Pi Computer [LINK] laying around, 512mb model and it was already housed in the perfect case, an indestructible Cool Trays Aluminum Case [LINK]. The RPi is a $35 dollar computer with 512mb of RAM and an ARM Processor, prefect for projects like this!