This is indeed a very informative topic.
There may be a leeway based on what few other people documented here: California sales tax on lease end buyout - be educated! | Inside EVS Forum
GHTech is correct about minimal driving of the vehicle once you have the title in your possession. If you can’t sell the vehicle within 10 days, you will need to record any miles required to sell the vehicle (e.g. prospective buyer test drives), and then complete a form from the California tax authorities.