For the purposes of this article, the following terms shall have the meanings respectively ascribed to them by this section:

(1) POLICY OF AUTOMOBILE LIABILITY INSURANCE. A policy delivered, or issued for delivery, in this state insuring a natural person as named insured or one or more related individuals, resident of the same household, and under which the insured vehicles therein designated are of the following types only:

a. A motor vehicle of the private passenger or station type that is not used as a public or livery conveyance for passengers nor rented to others; or

b. Any other four-wheel motor vehicle with a load capacity of 1,500 pounds or less which is not used in the occupation, profession, or business of the insured; provided, however, that this article shall not apply:

1. To policies of automobile liability insurance issued under an automobile assigned risk plan;

2. To any policy insuring more than four automobiles; nor

3. To any policy covering garage, automobile sales agency, repair shop, service station, or public parking place operation hazards and provided, further, that this article shall apply only to that portion of an automobile liability policy insuring against bodily injury and property damage liability and to the provisions therein, if any, relating to medical payments and uninsured motorists' coverage.

(2) NONPAYMENT OF PREMIUM. Failure of the named insured to discharge, when due, any of his obligations in connection with the payment of premiums on a policy of automobile liability insurance or any installment of such premium, whether the premium is payable directly to the insurer or its agent or indirectly under any premium finance plan or extension of credit.