On Dec 23, Tesla delivered to us defective new model Y, but assured us at the time that the 12-volt battery alert on the screen would go away--that they had already replaced that battery and that the alert would clear within a matter of hours. Relying on the delivery team, we took the car home but the alert didn't clear and the car couldn't access autopilot, TACC, updates, wi-fi -- nada. We returned the car to their service center, where they have tried a number of things to fix it, unsuccessfully. So far they are stumped. This car should never have been delivered to customer, and we have demanded that Tesla replace it with a new, properly functioning Model Y as ordered and paid for. Tesla has not responded. We are exceedingly disappointed.