Elon says he "led the design of the original Roadster"[1]. However, Elon is often loose with the truth - and even by his own admission in 2006[2], his role at Tesla mostly involved business and product strategy.
Really, the visual design of the Roadster is a highly modified Lotus shell. It was designed by a group of people, notably Barney Hatt[3]. Musk had strong opinions about how the car should look, and participated in key meetings with designers. You can think of him as the product owner for the visual styling of the Tesla's shell (but not the designer). This is impressive on its own, as he was also running a fledgling SpaceX at the same time.
Building a really nice version of the Lotus Elise shell is not what makes Tesla unique, though: their all-electric drivetrain and battery systems were revolutionary at the time, and they designed by a bunch of brilliant people like JB Straubel[4] -- not Elon Musk. Ze'ev Drori also deserves credit for bringing the Roadster from prototype to production and bringing the discipline needed to solve their early manufacturing issues.
Tesla's incredible marketing, though? The thing that let them hire best-in-class engineering talent and inspire those folks to work for long hours on changing the auto industry? The thing that let them raise money from Google and eBay founders? The thing that continues to inflate their share price to massive P/Es, even today? That's all Musk. He's the best marketer in the world, bar none.
It irks me that Musk is not satisfied with his incredible level of accomplishment and needs to also obscure the work of the people around him who made important contributions. It's been a successful strategy for him so far though, as evinced by the wide acceptance of his version of events and the resulting positive effect on the companies he's involved with.
I'll write a blog post about this with more research if people are interested.
[1] https://twitter.com/elonmusk/status/1596862790408568836
[2] https://www.tesla.com/blog/secret-tesla-motors-master-plan-j...