1. (a) The fees, taxes, penalties and interest accruing under article 21 constitute a lien upon all motor vehicles and vehicular units of such carrier. The lien attaches at the time of operation of any motor vehicle or vehicular unit of such carrier within this State and remains effective until the fees, taxes, penalties and interest are paid, or the motor vehicle or vehicular unit is sold for the payment thereof. Such liens are paramount to all prior liens or incumbrances of any character and to the rights of any holder of the legal title in or to any such motor vehicle or vehicular unit, subject to the following exceptions:

   1. (1) Any lien for such tax attaching on and after September 1, 1957 is subject to the lien of any indebtedness secured by a chattel mortgage or conditional sales agreement existing against a motor vehicle or vehicular unit previous to the time when the tax became a lien if:

      1. (i) such indebtedness was incurred in good faith to secure a portion of the purchase price of such motor vehicle or vehicular unit, and
      2. (ii) such indebtedness is secured by a chattel mortgage or conditional sales agreement duly filed as required by law, and
      3. (iii) 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.
   2. (2) Where additional taxes are assessed pursuant to section 510 of the Tax Law, no lien for any additional tax so assessed is enforceable after September 1, 1957 against any motor vehicle or vehicular unit which has been transferred in good faith to a bona fide transferee for value prior to the assessment.
2. (b) It should be noted, however, that a lien for additional taxes may be enforced against a transferred motor vehicle if the taxes were assessed prior to the transfer.
3. (c) A chattel mortgagee or conditional vendor who has repossessed a motor vehicle or vehicular unit which is subject to the truck mileage and fuel use tax lien may not sell such motor vehicle or vehicular unit at public or private sale unless five days' notice of the time and place of such sale is served, by registered mail, upon the State Tax Commission, Miscellaneous Tax Bureau. (See section 470.1[a], supra.)

Tax Law, § 506