UM confusion

May an injured passenger in a single car wreck stack UM coverage under policy on mother of tortfeasor driver, who lives in the mother’s home. The passenger is not a relative or household member of the mother.

Answer: No. Persons insured only by reason of occupying an insured vehicle (called Class 2 insureds) may not stack UM coverage. This is true whether the owner's vehicles are insured under separate policies (Babcock v. Adkins, 1984 OK 84, 695 P.2d 1340) or the vehicle being occupied is one of several vehicles insured under a single policy (Rogers v. Goad, 1987 OK 59, 739 P.2d 519, Stanton v. American Mutual 1987 OK 118, 747 P.2d 945).
Under these cases, your client as a passenger in one insured car will not be an insured under the coverage of the non-involved car.