IMO, the only way to sell a lease buyout to a dealer (Vroom, etc) in CA would be to follow these steps in this order:
- Get a buyout quote from your leaseholder and mail them a check. You must stop driving the car at this point. Any use of the car after this will trigger a use tax bill in CA. Pay them for whatever expedited title processing (and hope they don’t lose your check for that, like VWC did mine).
- Wait for the original title to arrive. The day it arrives, take it to the DMV, transfer the title into your name, and pay the sales tax. Pay for expedited title processing to speed this process up. At this point, your 10 day clock starts. ("The sale of a vehicle to a lessee by a lessor may be considered a nontaxable sale for resale. If the lessee transfers title and registration to a third party within 10 days from the date the lessee acquires title from the lessor at the expiration or termination of a lease, the sale will be presumed to be a sale for resale. Transfer of title and registration occurs when the lessee endorses the certificate of ownership.)
- Within 10 days, you need to receive the new title from the DMV and sign a bill of sale with Vroom, Carvana, etc. showing that you sold the car. This may be impossible, given the time it takes to get a title from the DMV, but the way the law is written, this is what is required.
- Use this bill of sale and the paperwork from the original title transfer to show that you sold the car within 10 days and request a refund of the sales tax paid. This should be technically possible using CDTFA-101, but I would contact the CDTFA first to find out exactly what documentation they will ask you to provide (call your local office - mine was incredibly helpful).
I would like to believe that there’s some leeway allowed in the 10-day rule, since my CDTFA office said their leadtime for processing an exemption was 8 days, but that’s another question that you should ask them before you embark on this journey.
This is not a fun process, and because of the way the 10-day exemption is timed (from receipt of original title to sale of vehicle), it may not actually be possible when companies like Vroom/Autonation are involved.
Hope this helps. If you manage to do it, please tell us about it. 
