Car insurance for non-car owners and car insurance for car owners is very little different, and the key reason is the number of cars that the non-car owners are insuring and who is on their policies. For example, if the non-car owners have a number of new drivers or teens on their insurance, then their premiums will be much higher than a car owner who has only themselves and their spouse on the policy with no children. Further, if they have no accidents and qualify for safe driver discounts, then their insurance may be far lower than the non-car owner’s insurance policy where the teens may have a number of accidents. Even though there may be a car discount applied.
For more info, see Non Owner Car Insurance: Pros and Cons