R.R. Asks: Can you still listen to the regular fm radio?
I don't listen to regular FM radio, which is why the car PC was so appealing as a entertainment system. I did briefly flirt with the idea of using the Griffin RadioShark USB FM Tuner ($60) to add FM listening capability. The RadioShark has an external antenna connection that I'm sure can be connected to the stock FM antenna on your car. MediaEngine supports a D-Link USB FM tuner, at least the documentation says so.
Overview

(0.2) Interior overview.
Batteries

(0.1) Batteries and isolator.