In Ontario ( not sure about other places). When you have the option to add "rental vehicle in case of an accident ", if you do not cause the accident you get coverage anyways. You don’t need to add it on. So if you have multiple vehicles in the house and you’re trying to save a bit, you can choose not to have this feature. second to that is, rental. Companies often will give you the same price if you ask.
Something I learned (the hard way), is some companies will not tell you when your payment hasn’t gone through until you hit the three month mark and they cancel your insurance for non-payment. So always make sure that payment is going through because “non payment” causes your premium to go up.