How much of his stake did he burn to buy twitter? Did Tesla get paid when its engineers were moonlighting at twitter? Musk has been promising self-driving car

How much of his stake did he burn to buy twitter? Did Tesla get paid when its engineers were moonlighting at twitter? Musk has been promising self-driving cars next year for, what, a decade now? Wasn't that supposed to be his best effort at building out AI? Or is he now saying that he was just kidding that whole time and now he's suddenly serious? What a riot