I'm in process of doing two out of system cars. The DMV lead time is 2 weeks for appointment down here. They have pointed out that first you need to get new "birth date" for the car. In DMV speak that the day that they renew your registration so California gets paid by us. CHP at least down here was a 3 week appointment time. DMV has inspected out of system motorcycles for me guess that some days the chicken bones or tea leaves are read in my favor. I had ex CHP lic. inspector do a car but as mentioned before B addition was not the same as a number addition or removal. I begged and groveled to the clerk to no avail. Much discussion on the LRXFE my guys say that it is not part of the VIN number. Later cars are all strung together but early cars have a space. I worked for an insurance company who used the last few digits to ID a vehicle just like cops do according to my retired CHP inspector.
Last few time they did not give me a red window temporary use permit as they said "we don't know if its safe till they inspect it." Print out a inf70 form and ask for help from the DMV when you are in process. Its not a hard form but one improperly checked box and it'll get sent back to you. At 5 bucks its the only bargain in the building and will print out names of date of first entry in to Cali.