As others have reported, if you have the money, CA has a 10d grace period on paying sales tax. If I were you, I would go this route.
Edit: there was a deleted (good) question from @Mikemikemike about title delays, CA has suspended their expedited title transfer, but they use Electronic Titles anyway:
https://www.dmv.ca.gov/portal/vehicle-industry-services/electronic-lien-and-title-program/
Perhaps the most useful benefit to lienholders is electronic notification when liens are perfected. Lienholders will no longer need to wait for a paper title in the mail to verify their liens are perfected. Instead, they’ll receive electronic notification the next business day, with owner and vehicle information included.
Plenty of anecdotes about selling to Vroom here