There&#x27;s no actual way of fixing this, if it ultimately relies on VINs. You can however mitigate it.<p>Let&#x27;s say you required an account and utilised authentication tokens, sure, that will stop unauthenticated requests. But what is stopping someone else from stealing your VIN and registering an account themselves? If you only allow a single account registration per VIN then what happens if the vehicle changes ownership?<p>VINs aren&#x27;t a &quot;shared secret.&quot; They&#x27;re a public fact. Instead Nissan should be utilising a secret number stored in the vehicle entertainment unit and user accessible, and they should add a button to change it when the vehicle changes ownership. Heck they  could even do a QR code if they really wanted registration to be as painless as possible.