From a California resident order showing the final price and being picked up at the Fremont factory:
"This address (my listed home address) will determine your sales tax and registration fees."
What's interesting is that Tesla doesn't show a breakdown of the "applicable taxes and fees". (I'm requesting this info). But based on the final figure, it looks like the sales tax IS based on my home address. In my case 8.75% vs 9.5% in Fremont, CA.
A suspicious person might wonder, "What are those fees?". In my case, they are over $700. Undercoating? Miracle paint protector? Dealer prep? VIP delivery service? Snack fee for plant tour? A full tank of electrons?