Well.. I have been doing a lot of thinking and research in the last while. My original plan was to setup a car pc and use an in-dash lcd monitor with touchscreen. I've realised that this may not be the best solution because my steering wheel blocks the view of the screen when I am in the drivers seat.
I have recently bought a pair of bucket seats off a friend that I plan to install this weekend. (will post pics) So my new plan is to custom build a console in between the front seats and build an lcd into the console.
Now to decide what size screen I want.