Sounds pretty damn awesome wileetundra!! Looking forward to those pics and thanks for plodding into uncharted territory.
I saw this company mentioned in the April 2007 issue of Car & Driver regarding unlocking the NAV screen while driving:
Prius Accessories
Price is around $229 according to C&D. They had to disassemble a good portion of the dash to install it too. I am not sure if they have a model yet for the Tundra.
re.ac.tor