I read your original post on you car pc upgrade a while back. But, lately (last few years) I only get on tt.net when I have spare time over a weekend once a month or two and read back until I start remember posts. Obviously, I was too late to reply to your original post.
Your solution is definitely more "balls out"!
This solution, correctly installed, could be pretty stealth!
I'll just use it as a tablet over the winter and try to get it installed in the Z this spring.