In both instances, KITT is an artificially intelligent electronic computer module in the body of a highly advanced, very mobile, robotic automobile.

KARR was voiced first by Peter Cullen and later by Paul Frees in seasons one and three, respectively, of the NBC original TV series Knight Rider.

KITT's Voice (Anharmonic) Synthesizer (for speech) and Etymotic Equalizer (audio input) allow his logic module to speak and communicate.

In episode 14 "Heart of Stone", this was changed to three sectioned vertical bars, as this design proved popular with fans as part of KARR.

KITT has a hidden switch and setting dial under the dash that either completely shuts down his AI module or deactivates certain systems should the need arise.

KITT also has an array of tiny audio and visual microscanners and sensors threaded throughout his interior and exterior which allows for the tracking of anything around the car.

In Episode 26, "Merchants of Death", the microwave system's power has been increased 3 times its normal strength, strong enough to bring down a helicopter at a limited distance.

In later seasons, a passive laser restraint system helped protect Michael and any passengers from the shock of sudden impacts and hard stopping.

The video display is also used for the Graphic Translator system (which sketches likenesses from verbal input to create a Facial composite), as well as for scanning or analysis results.

KITT also has an in-dash entertainment system that can play music and video, and run various computer programs including arcade games.

KITT is equipped with "Tri-Helical Plasteel 1000 MBS" (Molecular Bonded Shell) plating which protects him from almost all forms of conventional firearms and explosive devices.

One main feature of the redesign is that Super-Pursuit mode is added, consisting of improved rocket boosters for enhanced acceleration, retractable spoilers for aerodynamic stability, and movable air inlets for increased cooling.

The trailer is loaded with spare parts and equipment for KITT, and also has a computer lab where technicians Bonnie or April would work and conduct repairs and maintenance while in transit.

For example: on April 4, 2007, "one of the four KITT cars used in production of the television series" was reputedly being put up for sale for $149,995 by Johnny Verhoek of Kassabian Motors, Dublin, California.

The 1978 Dorsey trailer had been modified to carry race cars in the late 1980s and the original rear ramp door used to drive KITT in and out on the series had long been removed.

[6] The nanotech platform is written as needing the AI active in order to produce any of these effects, unlike the original car's gadgets and "molecular bonded shell" which allowed it to endure extreme impacts.

The car can engage an "Attack Mode", featuring scissor/conventional hybrid doors, which allows it to increase speed and use most of its gadgets (including turbo boost).

The vehicle had numerous 21st-century technological improvements over the 1980s Pontiac Trans-Am version of KITT, such as an amphibious mode (which allows the car to travel across water like a speedboat), a virtual reality heads-up display (or VR-HUD, which utilized the entire windshield as a video display), a microwave stun device that could remotely incapacitate a human target, a remote target assist that helps the pilot to aim and fire with a complete and perfect accuracy, voice activated controls, a fax machine, an infrared scanner that could identify laser scope rifles as well as hidden objects giving off heat, a more complex olfactory scan, a voice sampler that could simulate any voice which has been recorded into the Knight 4000's memory, a microwave projector that could cause the temperatures of targeted objects to quickly rise and either ignite or explode, and a thermal sensor that allows the Knight 4000 to watch and record what is happening in a particular place.

[13] After filming wrapped, the custom car was used on other TV productions of the time and can also be seen, albeit briefly, as a stolen supercar in CHiPs '99,[14] as repainted future police vehicles in Power Rangers Time Force, in an episode of the television series Black Scorpion in March 2001, and in a hidden camera TV series called Scare Tactics.

KARR (voiced by Peter Cullen) first appeared in "Trust Doesn't Rust" aired on NBC on November 19, 1982, where he seemingly met his demise at the end.

Trust Doesn't Rust was also printed in book form, written by Roger Hill and Glen A. Larson, following the story and general script of the original television episode, expanding some areas of the plot and adding several extra secondary characters.

Unlike KITT, whose primary directive is to protect human life, KARR was programmed for self-preservation, making him a ruthless and unpredictable threat.

KARR demonstrates a complete lack of respect or loyalty – on one occasion ejecting his passenger to reduce weight and increase his chances of escape.

When KARR is close to exploding after receiving severe damage; he willingly turbo-jumps into a mid-air collision with KITT, hoping that his own destruction would also spell his counterpart's.

One explanation of this change could be as a result of the damage he received after falling over the cliff at the end of "Trust Doesn't Rust", causing further malfunctions in his programming.

Instead of an automobile, a schematic display shows a heavily armed humanoid-looking robot with wheeled legs that converts into an ambiguous off-road vehicle.

[17] One of the reasons for KITT's attractiveness was in the fact that "domesticated" then-powerful technology (computers), making it "accessible, flexible and portable" in a way that was also "reliable and secure".

[20][21] KITT has also proven to be influential for the design of real-world computers for vehicles, with a number of studies noting that the science-fiction vision of the 1980s, portrayed in the show, is coming to be realized in the real life as of the early 21st century.

[22][23][24][25][26][27] Shaked and Winter noted that it was "one of the most appealing multimodal mobile interfaces of the 1980s",[28] although talking to computers in a way similar to humans is still in its early stages of maturing as a technology as of 2019.

Also in late 2004, 1/18 scale die-cast models of KITT and KARR were produced from ERTL complete with detailed interior and light up moving scanner just like in the series.