California Code, Civil Code - CIV § 2984.3

Any acknowledgment by the buyer of delivery of a copy of a conditional sale contract or purchase order and any vehicle purchase proposal and any credit statement that the seller has required or requested the buyer to sign, and that he or she has signed, during the contract negotiations, shall be printed or written in size equal to at least 10-point boldface type and, if contained in the contract, shall appear directly above the space reserved for the buyer's signature or adjacent to any other notices required by law to be placed immediately above the signature space.  The buyer's written acknowledgment, conforming to the requirements of this section, of delivery of a completely filled-in copy of the contract, and a copy of the other documents shall be a rebuttable presumption of delivery in any action or proceeding by or against a third party without knowledge to the contrary when he or she acquired his or her interest in the contract.  If the third party furnishes the buyer a copy of the documents, or a notice containing the disclosures identified insubdivision (a) of Section 2982, and stating that the buyer shall notify the third party in writing within 30 days if a copy of the documents was not furnished, and that notification is not given, it shall be conclusively presumed in favor of the third party that copies of the documents were furnished as required by this chapter.