(1) Such indebtedness was incurred in good faith to secure a portion of the purchase price of such motor vehicle or vehicular unit, and
(2) Such indebtedness is secured by a chattel mortgage or conditional sales agreement duly filed as required by law, and
(3) Such chattel mortgage or conditional sales agreement was not given, directly or indirectly, to any officer or stockholder of the corporation owning or having the lawful use or control of such motor vehicle or vehicular unit, whether as a purchase money mortgage or otherwise. The lien of such tax shall be enforceable, however, as to any equity after the encumbrance of such chattel mortgage or conditional sales agreement. In the event a motor vehicle or vehicular unit subject to such tax lien is repossessed by a chattel mortgagee or a conditional vendor such motor vehicle or vehicular unit shall not be sold at public or private sale unless at least five days notice of the time and place of such sale is served by registered mail upon the tax commission in Albany.