Does anyone know what the bulb size is for the little tiny bulbs that light up the buttons around the navi screen? I was thinking about changing the bulbs to a blue or a hyper white. Has anyone done this before?

 

They aren't bulbs per se, they are circuit board mounted bulbs. A member a long time ago was working on it, but never posted up the finished results... (circa June 2003). Here is his CarDomain site (He did a teardown). He did the same thing for the window switches too:
http://www.cardomain.com/ride/389428