Knight Rider/WMG

The real reason Garthe Knight wanted Michael dead was because he was jealous of him.

 * That would explain why he kept trying to kill Michael as opposed to, "getting the hell out of dodge".

KITT is built from the wreckage of a Cylon that crash-landed on Earth...
...Hence the wavering LED eyes and the unreproducible AI
 * Further evidence of this theory comes from the Galactica 1980 episode, "The Night The Cylons Landed"--

KITT is an amnesiac Transformer.
Knight Rider could be considered a prequel to the live-action Transformers films; that film did say all our technology was based on theirs...
 * This explains KITT's demonstrated mass-shifting abilities. All the parts for the other modes (like the van and 4-wheel drive) go wherever Optimus Prime's trailer goes. And the 2008 version of KARR practically has "Decepticon" written all over him.

KITT would only benefit from exposure to the Allspark.
Since he already has an AI, it would be the basis for his mind, which would make him better than the feral, animalistic ordinary devices transformed in this manner. After consulting with Optimus, KITT will decide to stay with his current job as the first 8-mode Autobot. (Normal, Attack, F-150, E-150 van, Flex, Crown Victoria Police Interceptor, "old school", Robot)

Mike is a robot.
The real Mike Tracer was killed in an incident when he was very small - perhaps one explaining why his father left his life, due to his connections with FLAG. Graiman made a robot copy based on a prototype AI he created that was loosely based on the original Knight Industries Two Thousand AI. It worked so perfectly that, eventually, Mike integrated and became indistinguishable from a normal human... and he was even given human "tells" like a mechanical heartbeat. Mike was accepted into the Marines because of meddling by government agencies - ; he can't remember what's happened because his memory banks of it were wiped.

KITT knows that Mike is a robot and has been specifically instructed not to reveal that fact.

Why is Mike a robot? Well, functioning on the level he did when is nearly physiologically impossible, and KITT's countdown was too accurate.

Las Vegas, Heroes, The X Files, The Stand and Knight Rider all take place in the same universe.
Both KR and Heroes have a Montecito casino; that casino is the setting of Las Vegas. Linderman was apparently running the casino, which would explain the Montecito's high owner-turnover ratio. It's possible that the Company was killing or persuading the previous owners, using people with powers, to get their hands on it.

Also, the Shanti virus, in an alternate universe, is what kills everyone in Stephen King's The Stand, except much earlier. (This is supported by King himself, who said that The Stand universe was an alternate version of ours). It may be because of time-travel, or it may be because the Company experimented with an early form of the virus. The Company's coverups would also explain all the weird stuff that keeps happening to Mulder and Scully, especially if you've read the "Last One Standing" fanfic.