That's pretty cool. Never seen that before. Just to be clear, a laptop is not an option? It seems like the obvious choice. I would still go for the AMD build. This is making we want to stick a computer in my VW but I'm sure I would need a second battery.
I have a laptop so I don't need one and Tiny I don't know your electrical system but this build is under 300 watts total, unless you have a over about a 1 kw rms amp for you speakers and subs most vehicles can handle it with a good starting battery. That said, I have a second battery, but I'm also running almost 3kw rms.