The ZEV credits that Tesla receives, and sells on, aren't paid for by taxpayers - they're paid for by other automakers.

Ultimately, it comes out of the profits of whichever automakers aren't producing enough low-emission cars.

Interesting. This is my first time learning about ZEV credits. That's actually pretty cool.

Gasoline is not subsidized, it is heavily taxed.

Yes, gasoline is taxed at the retail level (though not particularly heavily in the US).

However oil & gas production receives significant subsidies in many (most?) countries around the world, including the US.

In addition, oil used for things like aviation fuel, heating, power generation, and maritime fuels used for shipping, are typically completely tax-free.