All prepaid maintenance liens attach at the time of the first prepayment and shall be preserved from the time the lien attaches. It is not necessary to file or record any notice of the lien in order to preserve or perfect the lien although a customer may file this lien in the manner prescribed for perfecting liens under subch. III of ch. 409 regarding debtors who are located in this state.
Wis. Stat. § 779.89