Coincidence?
Or did Glen A. Larson just really like the cool effect?
From Wikipedia:
KITT's scanner is similar to that of Cylons from the science fiction series Battlestar Galactica. Glen A. Larson, the creator of both Knight Rider and Battlestar Galactica has stated that the two shows have nothing else in common and to remove any fan speculation, he stated in the Season One Knight Rider DVD audio-comments, that he simply reused the scanning light for KITT because he liked the effect.
In The Second Season Chapter 4 of Knight Rider ("Merchants of Death"), there is a funny scebe between KITT and Michael Knight and two bikers very similar to a scene from Galactica between two bikers and a spacial vehicle in the shape of a motorcycle that can fly and can also travel as a motorcycle (this Galactica scene was set in the Earth). Of course, Glen A. Larson was the creator of both series and the writer of both scenes.