This is something that will make you do a double take. Mio has a GPS unit (not found on their website) that was previewed on CNet, it is the Knight Rider GPS.
From what I saw on the video (which is disturbing in some spots..) they have lights on the sides which mimick KITT's "mouth" from the TV series. The screen shows the left-to-right bar that was on the front of the car, and the voice used sounds similar to KITT's voice.
Now, just going on the Geek / Nerd factor... this is a GPS I would have to have. Just something about hearing KITT asking where I would like to go and "talking" to me that just brings back the 80's.
But, since this is just a "First Look", no idea when it will come out, or for how much. I am sure that for the main GPS functions, this is no different than most other Mio GPS units.