Tesla made over half a billion dollars supplying products to other Elon Musk companies. Visual China Group via Getty Images/Visual China Group via Getty Images Tesla earned $573M by selling cars and batteries to SpaceX and xAI last year. Tesla also bought services from xAI and SpaceX, it disclosed. Musk's firms have often blurred lines, sparking investor concerns about conflicts of interest. One Elon Musk company made over half a billion dollars selling to two other companies in the Musk universe . Tesla generated $573 million in revenue last year, selling cars and battery systems to SpaceX and xAI, according to a regulatory filing uploaded on Thursday. Tesla said it made about $430 million last year by selling Megapack products — a lithium-ion battery system — to xAI, Musk's artificial intelligence company, and the maker of Grok. It added that it made about $143 million, mostly from selling vehicles to SpaceX, the billionaire's rocket company, last year.…