Section 344.51 - Financial responsibility for domestic rented or leased vehicles(1g) In this section: (a) "Lessor" means a person who, for compensation, leases a motor vehicle to a lessee to be operated by or with the consent of the lessee or who acquires a contract for the leasing of a motor vehicle from another person.(b) "Motor vehicle" means a self-propelled vehicle.(c) "Rental company" means a person who, for compensation, rents a motor vehicle to a renter to be operated by or with the consent of the renter or who acquires a contract for the renting of a motor vehicle from another person.(1m) No lessor or rental company may for compensation rent or lease any motor vehicle unless there is filed with the department on a form prescribed by the department a certificate for a good and sufficient bond or policy of insurance issued by an insurer authorized to do an automobile liability insurance or surety business in this state. The certificate shall provide that the insurer which issued it will be liable for damages caused by the negligent operation of the motor vehicle in the amounts set forth in s. 344.01(2) (d) . No lessor or rental company complying with this subsection, and no lessor or rental company entering into or acquiring an interest in any contract for the rental or leasing of a motor vehicle for which any other lessor or rental company has complied with this subsection, is liable for damages caused by the negligent operation of the motor vehicle by another person.(2) Any lessor or rental company failing to comply with this section is directly liable for damages caused by the negligence of the person operating such rented or leased vehicle, but such liability may not exceed the limits set forth in s. 344.01(2) (d) with respect to the acceptable limits of liability when furnishing proof of financial responsibility.(3) Any person violating this section may be required to forfeit not more than $200.1971 c. 278; 1977 c. 29 s. 1654 (7) (a); 1979 c. 102; 1995 a. 329; 1997 a. 48. A lessor is not liable to the lessee's insurer for monies that the insurer paid to a victim of the lessee's negligence. American Family Mutual Insurance Co. v. Reciprocal Ins. Service Exchange Mgt. Co. 111 Wis. 2d 308, 330 N.W.2d 223 (Ct. App. 1983). When a lessee's insurance was insufficient to cover all damages, the lessor's errors and omissions policy was required to cover remaining damages. Germanotta v. National Indemnity Co. 119 Wis. 2d 293, 349 N.W.2d 733 (Ct. App. 1984). No statute requires a self-insured entity under s. 344.16 to provide uninsured motorist coverage as part of the optional insurance it offers to its customers. Prophet v. Enterprise Rent-A-Car Company, Inc. 2000 WI App 171, 238 Wis. 2d 150, 617 N.W.2d 225, 99-0776. A car-rental company issued a certificate of self-insurance under s. 344.16 and subject to liability limits under s. 344.01(2) (d) and this section was not a self-insurer for purposes of an underinsured motorist clause that excluded coverage for a vehicle owned or operated by a "self-insurer." Bethke v. Auto-Owners Insurance Company, 2013 WI 16, 345 Wis. 2d 533, 825 N.W.2d 482, 10-3153.