Protective Shell
The Mach 5 has a deployable bulletproof bubble that protects the cockpit and the driver, but KITT sports a Tri-Helical Plasteel 1000 Molecular Bonded Shell that's impenetrable to everything short of a friggin' rocket launcher. Plus, it protects the entire car, not just the cockpit, so he doesn't have to worry about getting a slug through the radiator.
Advantage: KITT


Tires
The Mach 5's tires have retractable shields, which protect it from everything from stray nails to particularly pointy pedestrians. There's also a button on the steering wheel that causes the tires to regenerate. All KITT can do with his tires is inflate and deflate them at will. That's only handy if you have to park it in a bad neighborhood.
Advantage: Mach 5

Weapons
The Mach 5's front-mounted rotary saws are actually kind of badass, but they're no match for KITT's arsenal, which includes a tear gas launcher, ultramagnesium charges, and a friggin' flamethrower. It also has more cup holders.
Advantage: KITT


Speed
While it was claimed that KITT could hit a ridiculous 300 MPH with his busters cranked to full, the Mach 5 is allegedly packed with 5,000 horsepower—about as much as a full-size diesel-powered locomotive. Combine that with its superlight body, and you get speeds that would pull the driver's face to the back of his head.
Advantage: Mach 5


Appearance
It's purely a matter of taste, but it takes a special kind of nerd to pick the pointy, torpedo-like body of the Mach 5 over the sexy curves of the '82 Trans Am. It's probably because Pontiac spent years and millions of dollars on research and development making sure "chicks will be into it."
Advantage: KITT

Artificial Intelligence
Yes, KITT's internal computers are better than the Mach 5's stupid robotic owl, but there's no doubt that the novelty of a wisecracking car would wear off after a while. Keep that in mind next time you're in the market for a used robotic battle vehicle.
Advantage: KITT


Trunk Space
KITT is lacking in the cargo department, but the Mach 5 has enough room for a fat kid and a fully-clothed monkey, making it the clear winner.
Advantage: Mach 5


VERDICT: By a score of 6–3, the Knight Industries Two Thousand emerged triumphantly, but whatever you do don't tell it or he'll never shut up about it. I guess the Mach 5 should get another point in the humility category.