You may be paying the insurance as their condition for being able to drive it. Is the car titled in their name, or yours? If it's in their name, it's their car. They can take the keys. If it's titled in your name, they can't legally take the car away from you, but they can kick you out at 18. They are giving you a choice, and maybe a not-so-subtle hint that maybe it's time for you to leave the nest, fend for yourself. If you want the security of their nest for a while longer, then fly by their rules.