The California Vehicle Code Section 27001 states

(a) The driver of a motor vehicle when reasonably necessary to insure safe operation shall give audible warning with his horn.

(b) The horn shall not otherwise be used, except as a theft alarm system which operates as specified in Article 13 (commencing with Section 28085) of this chapter.

However, 95% of the times when I am startled by a car horn, the car is empty, and the horn has nothing to do with safe operation or a theft alarm system. Rather, the car is honking to let the owner know that he or she has just successfully locked the doors using a remote control - the so-called "honk-on-lock" feature.

Is this legal? Is it legal to sell a car which is configured to have this behavior? If not, why is the law not enforced? Would enforcement require additional legislative action? Proof of property damage?