Cal. RTC § 6285

There are exempted from the taxes imposed by this part the gross receipts from the sale of and the storage, use, or other consumption in this state of a mobilehome or commercial coach required to be registered annually under the Health and Safety Code, or of a vehicle required to be registered under the Vehicle Code, or of a vehicle subject to identification under Division 16.5 (commencing with Section 38000) of the Vehicle Code, or a vehicle that qualifies under the permanent trailer identification plate program pursuant to subdivision (a) of Section 5014.1 of the Vehicle Code, or of a vessel or an aircraft, when either of the following occurs:

(a) The person selling the property is either the parent, grandparent, child, grandchild, or spouse, or the brother or sister if the sale between that brother or sister is between two minors related by blood or adoption, of the purchaser, and the person selling is not engaged in the business of selling the type of property for which the exemption is claimed.

(b) The sale is to a revocable trust in which all of the following occur:

(1) The seller has an unrestricted power to revoke the trust.

(2) The sale does not result in any change in the beneficial ownership of the property.

(3) The trust provides that upon revocation the property will revert wholly to the seller.

(4) The only consideration for the sale is the assumption by the trust of an existing loan for which the tangible personal property being transferred is the sole collateral for the assumed loan.