The unfortunate part here is that the previous API used authentication, and the credentials were the same as your owners credentials for the Nissan portal. They released this version at the beginning of the year. The previous API endpoint appears to still exist and work.
I suspect that they may have dropped the credentials for the new API because they had so many problems with users figuring out what credentials to use for their mobile app. This is obviously a terrible solution, just speculating.
I wondered about hijacking cars by taking their VIN, but the process is not automated. It requires a call or two to Nissan to verify ownership before they will transfer the vehicle over to your account. This isn't to say you couldn't social engineer you way into the car, but you need more than the VIN. Incidentally you can't unlock the car remotely, at least not with the known endpoints :)
I suspect that they may have dropped the credentials for the new API because they had so many problems with users figuring out what credentials to use for their mobile app. This is obviously a terrible solution, just speculating.
I wondered about hijacking cars by taking their VIN, but the process is not automated. It requires a call or two to Nissan to verify ownership before they will transfer the vehicle over to your account. This isn't to say you couldn't social engineer you way into the car, but you need more than the VIN. Incidentally you can't unlock the car remotely, at least not with the known endpoints :)