@HOPE2  But if they get the credit from the dealer, there is no need to stop withhholding, right?

"According to Edmunds, “If you’re truly looking to get the best price on a used car, you’ll want to shop in December.” Dealerships, including Tesla, often have sales events at the end of the year to clear out inventory, make way for new models and hit quotas."

https://www.nasdaq.com/articles/6-ways-to-get-a-cheap-deal-on-a-tesla-before-the-end-of-2023

The supply of Teslas in January is not going to be any higher than usual, but the demand will greatly increase because of all the buyers waiting for the dealer tax credit.  This reminds me of when the price of a solar water heater went from $1,500 to $2,800 as soon as a $1,000 tax credit was available. 

But then, there's no telling what Elon Musk will do.