Yes.. there USED to be an arrangement between CA and some neighbor states like OR/NV and maybe WA (even though it's a state removed. You could pay some tax, but only up to your actual registration states amount and get a 30 day registration for CA for a fee and drive the car out. I think that ended a few years back.
Getting something like a European Delivery probably won't ever be possible due the financial mechanics of those programs.
Historically, most programs from Mercedes, BMW, Audi, Porsche, one could easily get a 7-9% discount off USA retail pricing and pickup the car abroad. (It was negotiable, so could be greater).
One got a factory tour, usually a hotel room for a night near the factory, and had the car to drive around Europe for a while.
The trick was, you HAD to drive the car around. The way the math worked for the domestic USA importer was the the car being imported in the end was actually USED and didn't have to be imported as a full value NEW value (of course the manufacturer importer never imported cars as a new RETAIL price, but it was higher than the depreciated value of the "used" car. You had to drive something like at least 250 miles before dropping the car off at the port or drop off location.
If you think about, their costs of shipping, transporting and delivering the car to you were basically the same, the VARIABLE was the reduced import price and thereby taxes and tariffs to be paid were less.
Also, for the most part the ED programs (okay, that's not a really good acronym to use for this I guess) were technically sold and facilitate by the domestic importer, NOT the dealer. The dealer didn't get the oppty to get the difference between what they paid the domestic imported and what they could sell the car for. They got something, guaranteed, but they could possibly get more by selling you a car on the lot-ever if the price you paid on the lot was the same.
Its still a fun program and I've done it many times, but I think today in our WANT IT NOW society nobody wants to wait.