This. Just got re-upped for $20 today actually.No, it’s $20 / month and it’s prepaid. Stop any time, no contract.
The $10 is if you DO have an AT&T phone, then you can add the car for $10 to your existing plan. For example if your phone has a 10GB plan, then you can pay an additional $10 / month to let your car use some of that 10GB.