I hacked my NAVI in early May and blogged about it:
http://www.averageadmins.com/blog/20...splash-screen/
I also posted some photos and some of the links I used to complete the task. Very cool! The only thing is, I am planning on performing an audio install (I already have all of the components... just waiting on a buddy of mine to have some free time) over the next 3 weekends and have to disconnect the battery which, according to most links I have seen about this, will revert the NAVI screen back to the factory default... That's why I roll with my hacked CD in the ride incase my battery goes dead, etc.
Very cool hack! Works like a champ!
Cocoa