Some things I've learned about it:
it seems to be a rebadged MOOV 300
it runs on windows ce -- this makes it extremely hackable
without installing any hacks I was already able to add a name that was not included with the unit.
my girlfriend really needed a GPS device, and I jumped at the chance to get this for her since she did enjoy the original show (must be the Hoff

so after playing around with the list of names, and realizing that Daniels had to actually say each name that the unit does have, I knew there had to be a folder with all those files in it.
the path to that folder is:
BEFORE PROCEEDING, MAKE SURE YOU ALWAYS BACK UP ALL DATA BEFORE MAKING CHANGES!!!! CREATE A DUMP FOLDER IN A SAFE PLACE ON YOUR DESKTOP OR WHEREVER AND BACK UP ALL FILES YOU INTEND TO CHANGE!!
X:\Program Files\Navman\SmartST_CE\Data\KITTData\Name (X being whatever drive letter your computer assigns to the unit.
the names are stored as wav files.
I also noticed a slight delay when you push on the greetings button in the preferences menu and figured that it must be doing something to cause that delay.
it's reading an XML file named "GreetingName.xml" that contains the list of names stored in the unit
the path to that file is: X:\Program Files\Navman\SmartST_CE\UserData\
armed with this information I made copies of the name Jennifer and Johnny on my desktop, and imported them into Audacity* and chopped away untill I had KITT saying the proper name, then exported the wav file.
*Audacity: A free, open source software for recording and editing sounds in Linux, Mac OS X, and other operating systems.
Audacity can be found here: http://audacity.sourceforge.net/" onclick="window.open(this.href);return false;
I then made a copy of the GreetingName.xml file and opened it up with Frontpage
copied the 2 lines dedicated to the name George, moved George down two lines and pasted my copy, replacing George with Genny in the correct alphabetical sequence with the rest of the names.
works like a charm, it even shows up in the preview mode when selecting a greeting name.
if you want to take names that were spoken in the show or add something else spoken by KITT from the TV show, this is the correct format for the name files:
wav file
bit rate 705kbps
audio sample size 16 bit
channels 1 (mono)
audio sample rate 44khz
audio format PCM
GOOD LUCK!!
KITT now greets my girlfriend correctly, I hope someone finds this useful.