It would be reasonable if what that app did was anything that actually needed internet servers to work. Why not just pair up the phone with the car, ad-hoc like you could with a PSP, or any sort of peer-to-peer between car-phone, and call it a day? Oh, right, because then you can’t create a service you can charge monthly for.
That people are willing to pay for effectively a remote temperature control and shutdown timer, that does not need to be an internet service to work properly, can and should be dunked on.
Time to begin the era of the DYI automobile. Buy a number of ~30v, high amperage batteries, an electric motor, jury rig the thing to a drivetrain and presto!