This is kind of crazy, Tesla at peak spent 4 billion $. And they used spend less then 2 billion $. And remember, Tesla is far more vertically integrated. Tesla has large spend in research for their battery and battery materials manufacturing. The make all their own chips, including even some on the data center. They also build robots. And do much of their own AI work.

I must be that Tesla prefers to have some research simply be considered as part of product development. While Mercedes does the opposite.