As of December 2017 the Buick Lucerne is no more, and while this is indeed a sad event, seeing as the full design and development of this particular project will never be realized, the concept of a custom RPi Driven and/or enhanced Vehicle Multimedia System is still not faded from my mind. 

My new vehicle is a 2010 Audi A4 Quattro 2.0L Turbo, which admittedly already boasts a fairly advanced Integrated Media System, the Audi Media Interface (AMI) and expandable Multimedia Interface (MMI), but with it also  carries the likelihood of creating new and interesting challenges and provides opportunity for additional capabilities (though possibly at the cost of added complexity....)

Either way, whether it be on my new car or ported into a different environment, it is back to the drawing board for now, but stay tuned and hopefully a viable plan for a new project will be along in the not too distant future.