Krebsbach v. Miller
In Krebsbach v. Miller, 22 Wis. 2d 171, 176-77, 125 N.W.2d 408 (1963), the supreme court identified three situations where implied permission may be found:
(1) when the first permittee, to whom the car was intrusted by the named insured without any express prohibition against letting another drive, retains possession of the car but turns over its operation to another while such first permittee remains an occupant of the car.
(2) where the named insured has knowledge that the first permittee is loaning the use of the insured vehicle to others and nevertheless remains silent. ...
(3) where for all practical purposes the first permittee is the real owner of the car but title has been taken in the name of the named insured for reasons of convenience, the general control and custody of the first permittee is such that, when he grants permission to a third person to operate the insured vehicle such operation is held to be with the implied permission of the named insured.