ok - leme see if I understand this...
you want to be able to run a PDA as a car computer, but you want to be able to plug it into a larger screen? do you already have the pda? there are some PDAs out there (I believe) that will let you hook up to VGA....I know the Dell Axim X50v is a VGA screen, might be able to use that
You can find it here: http://www1.us.dell.com/content/prod...=19&l=en&s=dhsVGA-Out Support with optional VGA Presentation Bundle
so you just want to use the memory off of the PDA, and not a hard drive? so i take it you want to use cf or sd for your storage?
what else are you wanting to do with this set-up? is it just going to be used for GPS/navi?