My current BMW comes with both a Wi-Fi chip and a 3G chip, at no recurring cost. Seems quite feasible for me to connect to the car via app and pay on my phone.
> Seems quite feasible for me to connect to the car via app
Who says that app is available after 3 years? Or the servers required for using it?
It might be even removed from the app store, and you can't sideload it with your iPhone.