After a lot of thinking, and inspiration, I have decided to go ahead with an old laptop I have (Dell Inspiron 4100) and use that. I have very little soldering / electronics skills, so building a system like vincentvega has in his car, is pretty much too far from my humble capabilities.

This pretty much has to be bolt-on/clip-on/screw-on/silastic-on.

After some research and discussions with friends, I discovered one of my mates has a spare, brand-new docking station model PDX C/Dock II at his work, and was willing to swap it for a bottle of Jim Beam. SOLD!
(same model for sale on ebay USA.. good demonstration of extended capabilities of the docking station.)
After the quick transaction, I thought I was well into the beginnings of my carputer. Until I hit a pothole -
I discovered the dock is for the wrong model of laptop.
After some quick searching, I found an equivalent model laptop for rather cheap on ebay... waiting now till the auction ends. *fingers crossed*
The good news is that my now 'parts' laptop (complete, albeit burnt out LCD/inverter) is 100% compatible with the 'other' model laptop, and the only differences are the chassis' themselves.
I just wanted to throw a couple of questions into the air -
Dane: Which model of touchscreen LCD can you reccomend? An indash retractable display isnt compulsory anymore... i would be happy with an ordinary mounted one. which model would you reccomend? I tried logging in onto the mp3car forums, to no avail - they appeared to be shut down or something.
cheers
alex