This has become an interesting exercise.

My statement about the "farm vehicle" is incorrect because it omits the word labor.  I had never heard the term farm labor vehicle before but when I looked up the CA defination and copied it into my subsequent post, that is when I understood it to mean a vehicle to transport workers (labor).  I was thinking of it as a farm "work" (labor) vehicle as in a "work truck".

As to eddiedry's question, he was specifically asking about the CA law, which he quoted, and he used the term "migrant" in his question.  The actual law doesn't refer to migrant workers, nor does it apply to migrant workers, but rather all farm workers regardless of stripe.