California Code, Health and Safety Code - HSC § 44014.7

(a) The department shall require 2 percent of the vehicles required to obtain a certificate of compliance each year in enhanced program areas to receive their certificate from a licensed smog check station certified pursuant to Section 44014.2.

(b) The department may require a number not to exceed 2 percent of the vehicles required to obtain a certificate of compliance each year in basic program areas to receive their certificate from a licensed smog check station certified pursuant to Section 44014.2.

(c) The vehicles specified in subdivisions (a) and (b) shall be selected at random. The department shall select the vehicles and the Department of Motor Vehicles shall notify the owners of their obligation under this section pursuant to Section 4000.3 of the Vehicle Code. Selection shall be made from vehicles in an area where a test station is located.