All tax BS aside as that can vary so much in every area (I only pay a 0.5% new car excise in my state), I think we should always discuss the price of the car itself and getting an almost $2k dealer discount is not an easy feat, but is more possible in states with high sales taxes it appears as I got mine (exactly like OP, magnetic with black wheels only) for $18250 and that was only a $1250 dealer discount and the $3000 rebate... so to me, $17,750 is $500 less than I paid for mine, so I think that's a good deal!
Taxes don't have much to do it with it, it's the information you have...
Some areas of the country are heavy in truck sales, they will get one or two Focus ST/Fiesta ST's and they will be on the lot 90 days or more. Why? Because in truck country who wants to drive a tiny car? Only broke people and even then they get the base model S sedan anyway.
Also while California is a very densely populated state it still remains that over 45% of the population is east of the Mississippi, which means there is far more competition for people looking to buy cars.
That is why price drops are more successful and more frequent back east.
All that said, rule number one in getting the best price is to pit dealerships against each other. If you call Ford directly they will tell you every dealer in a 500-1000 mile radius that has a Fiesta ST.
Rule #2 don't get locked in on color and options. None of the colors the car is offered in are ugly and if you worried about what others think we're already off to a bad start. My Focus ST was Race Red ST2 and sat on the lot for more than 90 days. They were happy to get rid of it and my first offer was a price a dealership in Baltimore was going to sell me but we couldn't agree on the trade value of the Hyundai I mentioned earlier. They agreed to it (not even one counter offer), I drove out the next day, signed all the paperwork and drove home.
I paid $24,295 on a car with an MSRP of $29295. That includes private cash ($750) and rebate ($1250). The rebates back around Memorial Day were much more aggressive but I was waiting for my credit score to update.
There isn't much margin in the Fiesta ST, but that does not mean there aren't incentives directly from Ford to the dealer that are almost never mentioned.
Getting a base FiST for under $17K is possible, I've seen it. go back further in this thread and you'll see how often it's happen.
I know people that got base Focus ST's for $19K, MSRP was $24,600 or something.
All my info comes from James Bragg -
https://fightingchance.com/