Cal. Rev. & Tax. Code § 6379

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 any used mobilehome, as defined in Section 18014 of the Health and Safety Code, which is subject to property tax pursuant to Part 13 (commencing with Section 5800) of Division 1, or any used floating home, defined and subject to tax pursuant to Section 229.