Use of Owners car Australia

Yes, it’s a 16 year old Hyundai i30. They have 2 other cars, so this is just a spare one they use for hauling building materials, plants, etc.

Would renting a car for a month be an option?

We used a homeowners car in Sydney a few years back. She added us as named drivers and we were all amused that the premium went down and they gave her a refund!