§ 348. Transactions subject to article by agreement. Parties to a motor vehicle lease agreement that is not a retail lease agreement, as defined in subdivision five of section three hundred thirty-one of this article, because the vehicle is not being leased by a natural person primarily for personal, family or household use may agree in a writing signed by them that the agreement is subject to this article. If the parties so agree, the agreement is a retail lease agreement for the purposes of this article.