Are there phones that can be used only when necessary? Like if my vehicle dies unexpectedly?
i'm in a similar situation as you, wanting a phone for car for emergencies.
in the usa, there is no good solution for this that i am aware of.
my understanding is this:
1. all cell phones have to be allowed to dial 911 even on bad sim card and no plan -- so for REAL PURE emergency 911 access, yes you can use almost any cell phone and not pay for a plan.
2. but if you hope to be able to call any other number besides 911 you are going to have to expect to pay some kind of yearly fee whether you use your phone or not.
3. there are plans targeted at people who rarely use their phones (like me), but the cheapest i found is something around $100 a year. tmobile has a pay-per-day-your-phone-is-on plan for $3/day, but they still force you to pay a minimum and it ends up being about $100 a year.