TOKYO -- Toyota Motor and Volkswagen each sell 10 million cars, give or take, every year. Tesla delivered about 367,500 in 2019. But when it comes to electronics technology, Elon Musk's scrappy company is far ahead of the industry giants.

This is the takeaway from Nikkei Business Publications' teardown of the Model 3, the most affordable car in the U.S. automaker's all-electric lineup, starting at about $33,000.

What stands out most is Tesla's integrated central control unit, or "full self-driving computer." Also known as Hardware 3, this little piece of tech is the company's biggest weapon in the burgeoning EV market. It could end the auto industry supply chain as we know it.

One stunned engineer from a major Japanese automaker examined the computer and declared, "We cannot do it."

The module -- released last spring and found in all new Model 3, Model S and Model X vehicles -- includes two custom, 260-sq.-millimeter AI chips. Tesla developed the chips on its own, along with special software designed to complement the hardware. The computer powers the cars' self-driving capabilities as well as their advanced in-car "infotainment" system.

The Model 3's "full self-driving computer" consists of two boards: one with custom AI chips for autonomous driving, and a media control unit for the "infotainment" system. A water-cooled heat sink is installed between the two boards. (Nikkei xTech)

This kind of electronic platform, with a powerful computer at its core, holds the key to handling heavy data loads in tomorrow's smarter, more autonomous cars. Industry insiders expect such technology to take hold around 2025 at the earliest.

That means Tesla beat its rivals by six years.

The implications for the broader auto industry are huge and -- for some -- frightening.

Tesla built this digital nerve center through a series of upgrades to the original Autopilot system it introduced in 2014. What was also called Hardware 1 was a driver-assistance system that allowed the car to follow others, mostly on highways, and automatically steer in a lane. Every two or three years, the company pushed the envelope further, culminating in the full self-driving computer.

There should be nothing stopping Toyota or VW from doing the same much earlier than 2025, considering their immense financial resources and vast talent pools. But technological hurdles are not the reason for the delay, according to the Japanese engineer who said "we cannot do it."

The real reason for holding off? Automakers worry that computers like Tesla's will render obsolete the parts supply chains they have cultivated over decades, the engineer said.

Such systems will drastically cut the number of electronic control units, or ECUs, in cars. For suppliers that depend on these components, and their employees, this is a matter of life and death.

So big automakers apparently feel obliged to continue using complicated webs of dozens of ECUs, while we only found a few in the Model 3. Put another way, the supply chains that have helped today's auto giants grow are now beginning to hamper their ability to innovate.

Young companies like Tesla, on the other hand, are not shackled to suppliers and are free to pursue the best technologies available.

Our teardown underscored this in another way as well.

Most parts inside the Model 3 do not bear the name of a supplier. Instead, many have the Tesla logo, including the substrates inside the ECUs. This suggests the company maintains tight control over the development of almost all key technologies in the car.

And with this hardware in place, Teslas can evolve through "over the air" software updates. Right now, the vehicles are still classified as Level 2 or "partially autonomous" cars. But Musk has stressed that they have all the necessary components -- "computer and otherwise" -- for full self-driving.

From software to electric drive systems, Tesla is steadily bringing more development tasks in-house. If this strategy succeeds, competitors will have little choice but to follow suit, upending their old business models and supply chains as they try to overcome Tesla's head start.