The 2012 Hollywood Christmas Parade!

[HowardC]

Rog:

The KITT with the yellow scan bar actually IS KITT's evil twin KARR (Knight's Automated Roving Robot). It was the prototype for KITT that went evil and was featured in a few episodes as well as being the main villian of the Knight Rider video games. Some confusion might come from the fact that in the first appearance he also had a red scan bar (that scanned differently) but in subsequent episodes it was yellow. By the time he appeared in the video games, he was given a two-tone paint job, with his ground-fx painted gun metal gray.

In the first episode it was actually voiced by Peter Cullen... so yeah, Kitt with Optimus Prime's voice! I think Frank Welker went on to do him in later episodes and he was given a more generic bad guy voice.

I'm genuinely suprised you didn't know that!