The CA DMV web site never actually refers to a "title search".
But this seems like a likely place to start from their site:
Who To Contact
Driver License (DL)/Identification (ID) Card or Vehicle Registration
Submit your request on the appropriate form. Forms available online are identified by For the following forms (up to 15 copies each), call (916) 657-8098 or write DMV Information Release Unit, M/S G199, P.O. Box 944247, Sacramento, CA 94244-2470. For large quantities of forms, write to: DMV Materials Management Unit, 4201 Sierra Point Drive, #112, Sacramento, CA 95834-1998.