Overvalued, maybe. But comparing last year production of cars is in my opinion a bad metrics to compare Tesla to other automakers.

First Tesla is growing fast so that $50k will drastically go down in the coming years.

Tesla is more vertically integrated so you have to include the valuation of all the dealerships, parts of their suppliers, the charging network, ...

And third there are the “other” businesses like the battery storage, solar roofs, software revenue, ...

So overall the numbers of cars produced is probably too simplistic to compare them.