As RandyRosenberg has told me/us, it VARIES so wildly across California that the concensus has been, there's no consistancy, other than the fact they will ALL take your money. Thank god some things don't change.
Having said that, my horror story was based around the VIN. At the DMV, I did not have my "LEGAL" VIN, but I substituted my "Serial Number" from FFR. Well, that came back to bite me in the end. I would recommend that you tow your SPF or whatever, to a CHP to get the VIN applied. The car does NOT need to be "running" to get a VIN, however, they are looking for major components such as the transmission, engine and possibly rear-end. Of course the MSO from the manufacturer of the body/chassis.
Of course if it's "drivable", it's recommended you get your TOP first. Otherwise, you may also get a ticket from the CHP on top of the VIN as odd as that might sound.
If you cannot get the VIN this week, well, you'll have to put on your most patient and puppy-eyed game face on, and convince the clerk it must remain blank until the CHP issues the VIN. Remember, the clerks only get this weirdness once a year, and while 500 SPCNS registration spots sounds like a lot, California contains millions of people so it's a very tiny percentage from the DMV's perspective so cut them some slack. If you've waited in line as often as I have (6 times) you can see some very angry people with elevated voices talking to both the clerk and the supervisor. All I can do is humor them and let them know their job is appreciated and who knows? Maybe you'll get better cooperation on your registration.
Good luck to all you. I'm just freakin' glad I'm done this year. It was a bit of hell.