Not quite the same, but in the UK there was a chain of high street jewellers called Ratners. In the early ‘90s Gerald Ratner, the founder, made some jokes about the low quality of the products at a talk for the Institute of Directors, including famously comparing them negatively to a prawn sandwich from Marks and Spencer. Unfortunately the talk was videotaped, and was all over the news shortly after. It killed the brand, and lost Ratner his job, although it didn’t kill the company as they owned other brands like H Samuel that they pivoted to.

Tesla car’s don’t have a great reputation for quality or service.

They were among the first and the cars were good enough to persuade people, but there are many alternatives now. People are less likely to pay a premium for Tesla.

And the brand is irremediably damaged by Elon’s polarising politics.

Being off-putting to a large part of your market is bound to have negative effects on your sales.

Tesla is in a very peculiar position as an automaker, P/E ratio (price of the stock compared to earnings) is extremely optimist regarding the potential, with self-driving, robots and overall market dominance.

But all of that is not real, it is, at best speculative, and the cars themselves are not great, especially when compared to other EVs.

The huge valuation of Tesla will crumble dramatically as soon as investors stop believing the promises. And having poor/declining or even stagnating sales is very likely to trigger some close scrutiny and doubts.