Sorry, but the RoadStar package doesn't include coverage for car co-op vehicles.
The RoadStar package includes rental vehicle coverage. But this coverage doesn't apply to car-sharing co-ops. That's because they don't operate the same way as rental companies. For example, you join a co-op as a member and pay annual fees. Co-op applicants need to have an OK driving record but vehicle renters don't. Co-op's also include gas and insurance in their pricing. Rental companies, on the other hand, may charge extra for these.
To find out more, you might want to check out some car co-op websites to compare rates and insurance coverage.