(a)
A person shall not sell a product or device that obscures, or is intended to obscure, the reading or recognition of a license plate by visual means, or by an electronic device as prohibited by subdivision (c) of Section 5201.(b)
A person shall not operate a vehicle with a product or device that violates subdivision (a).(c)
A person shall not erase the reflective coating of, paint over the reflective coating of, or alter a license plate to avoid visual or electronic capture of the license plate or its characters by state or local law enforcement.(d)
A conviction for a violation of this section is punishable by a fine of two hundred fifty dollars ($250) per item sold or per violation.
Source:
Section 5201.1, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH§ionNum=5201.1..