Wis. Stat. § 895.048
The owner of a motor vehicle or motorboat which, while being operated by the spouse or minor child of such owner, is damaged as the result of an accident involving another vehicle or boat, may not recover from the owner or operator of such other vehicle or boat for such damages, if the negligence of such spouse or minor child exceeds that of the operator of such other vehicle or boat. In the event that it is judicially determined that a spouse or minor operator of the motor vehicle or motorboat is found to be guilty of less than 50 percent of the causal negligence involved in an accident, then in that event the owner of the motor vehicle or motorboat involved shall be entitled to recover in accordance with the contributory negligence principles as laid down in s. 895.045. For the purposes of recovery of damages by the owner under s. 895.048, and for this purpose only, the negligence of the spouse or minor operator shall be imputed to the owner.
Wis. Stat. § 895.048