Warning: contains spoilers for Black Panther Legends #2!
Marvel's Black Panther is the king of one of the most secretive nations on the planet, but the secrets of Wakanda's technology were spilled long ago, and one Marvel superhero knows all of them. Wakanda is highly advanced to the point of being decades ahead of most so-called first-world countries, and perhaps even more so in the Marvel Cinematic Universe. But even Wakanda fails to hide their true level of technology from their neighbors every now and then, as is the case in Black Panther Legends #2.
In the new Black Panther Legends series, Marvel examines T'Challa's past as the prince of Wakanda. Learning from his mother and father, T'Challa strives to learn how to become a good king. He was raised alongside his adopted white brother Hunter, who will later become the White Wolf and T'Challa's first very personal enemy (though there will be more throughout his life). But before he could become king and the Black Panther, T'Challa had a fateful run-in with a woman who would one day be his wife: Ororo Munroe, better known as Storm.
Missing his father after his murder, T'Challa wanders the Serengeti, a lost soul. He's quickly beset by bandits who seek to hold him for ransom, but they're attacked by Storm, who creates a whirlwind that drives the thieves away. Later that night, Ororo explains what she knows about Wakanda. Rumor has it that in T'Challa's home, "...your cars have wings...and that even the living have ghosts." Storm isn't that far off: one month later, Shuri contacts T'Challa via a hologram, and Storm sees everything.
Storm somehow knew that Wakanda possessed flying cars and hologram technology before she even saw working examples of both. This means that Wakanda isn't nearly as good at hiding their technological prowess as they think they are. When Storm sees the truth, she becomes angry at T'Challa - and by extension, Wakanda itself - for abandoning other African nations without lifting a finger to help. The technology within Wakanda could transform Africa, but the Wakandan elders elect to keep their secrets well hidden.
Years later, Storm would reencounter T'Challa and eventually begin a long relationship. The two would even become married, and Storm would now see Wakanda for herself. But the events in Black Panther Legends #2 reveal that Storm knew about Wakanda even as a child, which meant she was told these secrets by others; Black Panther's country is clearly not as adept at keeping technology to themselves as they believe themselves to be.