Automobile Insurance — Substitute Vehicles
When in need of a substitute or temporary vehicle, that vehicle would be determined by your automobile policy language. Some insurance policies define a temporary substitute vehicle as "a car not owned by you or your spouse," if it replaces your car for a short time.
Other policies specifically exclude coverage for "any vehicle, other than your covered auto, which is owned by any family member or furnished or available for regular use of any family member."
Read your policy language to determine what would be covered or excluded from your automobile insurance policy.