Municipalities may finance the construction of public parking facilities by issuing bonds or notes, which bonds or notes shall conform to and be issued in accordance with the provisions of N.H. Rev. Stat. Chapter 33 insofar as the same may be applicable. All such bonds or notes shall be issued for public parking facilities pursuant to a plan as provided in this subdivision which provides that an amount equal to at least 50 percent of the principal of such bonds or notes are to be assessed as provided in this subdivision, raised by motor vehicle permit fees as provided in N.H. Rev. Stat. § 261:154, or funded from the revenues of the parking system, or any combination thereof, shall at no time be included in the net indebtedness of the municipality for the purpose of ascertaining its borrowing capacity.