For the overwhelming majority of Californians who set up a revocable living trust there is simply no need to put your car into that trust. The DMV has simple processes in place to transfer the car after death and without going through the probate process. Here is a link to that California DMV web page. Other people have their spouse or other loved one on title and that works as well. However, make sure there are no insurance gaps if you put a third party, like your adult child, on the car title. Might be best to do a payable on death designation!?
However, some people want to put their car into the trust no matter what. If so the DMV has forms for that as well. Here is a link to that California DMV web page.