If the only reason you would be adding your girlfriend to your policy is to save money, I wouldn't recommend it. At the end of the day, your insurance company would be insuring an additional person and vehicle so regardless of the multi-person or multi-vehicle discount
you would receive, it probably wouldn't offset the additional insurable interests. If, however, your girlfriend does live with you and you'd like her to be able to use your vehicle, you'll have to add her to your policy. If you're looking for ways to save on auto insurance in general, see our guide to cheap car insurance in Brooklyn here
. It might not be that you need to have another driver and vehicle on your policy, but get a different policy altogether. Best of luck.