After being buried all this time, K.A.R.R. curiously has a number of minor changes from his first appearance, including: The scanner at the front is now of a greenish yellow (instead of red). His scanner now makes a sound identical to K.I.T.T.'s (instead of the deep 'drone' noise of the original). His license plate now reads 'KARR' (instead of the original 'KNIGHT'). The sound of his engine now more resembles K.I.T.T.'s (with some additional effects), instead of the fierce "roaring" engine sound previously. The casing around his voice modulator is slightly different.
As John drives KARR out of the sand, the bonnet, roof, rear window and rear bumper have a large amount of sand on them, but in the next frame just a couple seconds later, the car is totally clean.
When John first peers into KARR and sees the inside ("Man, you won't believe this dash!") the red POWER and AUTO buttons on the right-hand side are missing their labels.
KARR has his bumper and lower panels painted gray. When KARR is destroyed, Michael pulls over and KARR's front bumper is clearly visible in the sand and is inexplicably black, instead of gray as it was moments before.
K.I.T.T. claims to have discovered "turbine fuels" on the beach where K.A.R.R. was trapped for two years. Turbodrives use exhaust gases, not hydrocarbons, to power them.
When KARR is on the road again during the first twenty minutes it is a replica of KITT, but then suddenly the appearance changes with gray panels on the side, as with the toy model of KARR. During KARR's first conversation with John in the garage, KARR does say he wants to alter his appearance, although he never says why.
In the showdown between KITT and KARR a view of sparking and burning circuit boards are seen. The circuitry is that of an RCA XL-100 (chassis CTC-71) color television.
K.A.R.R.'s speedometer's L.E.D. bar-graph display is non-proportional compared to the digital (numerical) readout showing the car's speed - the bar-graph display is marked from 0 to 200 m.p.h., yet it is lit more than halfway across when the car's speed is shown by the digital readout to be only between 70 and 80 m.p.h.
As John drives KARR out of the sand, you can clearly see the rear wheels have been jacked up to make the car easier to drive out. In the next scene, they're at their normal height.
After Michael drops off John, Devon calls him on KITT's monitor, which is positioned to the right of the driver. Rather than talking and facing the video monitor, Michael is instead talking to and facing the steering wheel.
During the final climax between KITT and KARR, several shots of KARR's front bumper, on the bottom left, reveal that the paint is chipped and scratched, even though KITT and KARR are meant to be impervious to scratches and damage.
When K.I.T.T. and K.A.R.R. go head to head on the jump at the end, you can see K.I.T.T. getting blown into a backwards spin and falling down, and then the next shot they are landing like they jumped right through K.A.R.R.
Since John was totally unfamiliar with KARR how would John have known of or needed to plug in the connector under KARR's dash since KARR was already running.
When John and Mandy drive KARR for the first time, John requests music. A light illuminates on the display saying TAPE and "Jump" by the Pointier Sisters begins to play. John drops Mandy off and again requests music and "Self Control" by Laura Branigan starts. If KARR had been buried and disabled on the beach since 1982, there is no way he would have even had access to either of these songs as they were both not released until 1983.
When K.A.R.R starts driving on the beach, the crew is visible in reflections on the side of K.A.R.R.
During the climax between KITT and KARR, after KARR demonstrates the laser, a close angle of KITT is shown as he says "the men in the armored car". At this angle, some crew equipment is visible on the right-hand side of the screen.
As Mandy approaches KARR on the pier, the reflection of a crew member wearing a red baseball cap is visible on KARR's front panel.
When Michael arrives at Mr D's Marine to confront KARR, KITT comes to Michael's rescue and the actor clearly isn't David Hasselhoff, but a very obvious stunt double.
After John discovers that KARR can talk, he tells KARR that he'd probably be happier with somebody else. As he starts walking away, a microphone cable and bulge from behind his tank top is visible.
When John activates KARR by connecting the wires on his dash, KARR's voice-box lets out a loud rumble noise. Given that John is only a couple feet away, with the door wide open, he should've heard the noise easily and recognized immediately that KARR talks.