Bad in terms of awful script or horrible storylines ?
Hmm, I'm thinking more the 1997 ripoff which was... quite bad. Just for starters, one of the major themes that was repeated throughout Knight Rider was "One person doing the right thing can make a difference."
The opener was this...
So yeah, open up with contradicting the main theme of the previous show, also the new cars appear to be basic models rather than something clearly advanced and modified as KITT was (Such as lacking KITT's "Cylon" eye, and having regular dashboards instead of what KITT had). Adding insult to injury, they made them all Fords when KITT was a Pontiac, during a time when people were extremely loyal to the brand. There was a heavy focus on superweapons and supervillains rather than
Knight Rider's focus on stopping things like organized crime and protecting the innocent.
The writing was so dumb many fans speculated that the creators were actively
trying to make the worst possible spinoff, as a slight against the original creator or to kill the Franchise in order to make room for another pet project.