Tesla's average transaction was $65K in 2022. There were 1.3 million transactions. That's $84.5B in transactions. Companies are typically valued at 7x their transactions which would be $591.5B - which we'll just call $600B. If Tesla is currently valued at $400B then they're undervalued by 33% and that would put Tesla at a BUY.
These are all back-of-the-napkin calculations and assumes Tesla will sell as many cars in 2023 as they did in 2022 and in fact will continue to do so for the foreseeable future. I'm not an automotive industry expert but I don't see any reason why Tesla wouldn't. I think part of the reason Tesla's stock pulled back so much in 2022 is the realization that Tesla may not have that much GROWTH left.