ZipCar seems to have gottwn this right, probably because it was developed years ago. You have a card, and it works for your car even without cell service afaik.

ZipCar seems to have gottwn this right, probably because it was developed years ago. You have a card, and it works for your car even without cell service afaik. Unfortunately zipcar is declining where I live so I canceled my membership. They removed the zip cars in my neighborhood and I see zip cars around less often in general.