Let alone power it up and drive it.
What happens if the thing is outside a cellular service area? Are you stranded? I guess they don't have the range to do that so it's not as big a problem as it sounds.
This is, however, why it is an extremely bad idea to build any system that has to "phone home" before it will work. I don't care what you're talking about, whether it's a car or a video game or a can opener. If the computer goes down, the one from which you need to get permission to use the product you bought, you can't use it. If the network connection between your product and that computer is interrupted for any reason, you can't use it. If someone steals your phone/tablet/whatever, and you can't run the app?
Is there a backup? Keys? A dongle? Anything?
While Tesla's app helps you unlock the car, you can still use a key card, an option key fob, or the app without needing to connect to the internet. But some people who didn't have the key card or the fob, and were logged out of the app, had to wait at the time of reporting.All right; that makes sense. It was users who thought they didn't need to keep their backups outside the vehicle.
Here's an idea, then: you keep the keycard in your wallet with your driver's license, and keep your wallet on your person. Or pay a little extra for the key fob and attach it to your keys, and keep them on your person. Don't leave it in the car.
Dumb, all around.