This project just took a turn in a different direction. I need analog pins to interpret all the raw data, and the RPi only has digital inputs. I thought about using the Beaglebone Black as it does have analog in, but it's only mini-HDMI output for video and I have an RCA 7 inch screen that I'm utilizing. The Arduino UNO has enough analog pins to do exactly what I need, but no visual outputs without a shield. HOWEVER, I found out that with a 1k and 470 ohm resistor and some soldering, I can make pins 7 and 9 output video to RCA with the TVOUT library. The UNO (and subsequently the Pro Trinket 5v) can handle the input power voltage straight from the car's battery and the analog pins just need to be stepped down with a 10k and 3k ohm resistor to around 3 volts. So this has basically just become and Arduino digital dashboard. I'll be poking, prodding, and building within the week, so I should have new images and such soon.