2018 Nissan Armada

We have a Nissan Armada that the Multi AV unit / computer has failed (Part # given to us is 283876GY4D). The vehicle is barely 4 years old. We were quoted a $3,800 repair and Nissan has told us there is no help they can provide. Despite having purchased a 7 year 100,000 mile limited warranty this part isn't covered. Investigating online into the issue we have found that this component is problematic in many vehicles and has service bulletins associated with it. Nissan is stating that because it is GPS, Radio, and cabin comfort it is not a safety issue. HOWEVER, it goes beyond that. We have stated several times to Nissan, that as this unit continuously reboots and malfunctions the windshield defrost / fog clearing aspect of the vehicle does not work. We have had several instances where we've had to pull over in less than desirable locations in order to manually clear our windshield. As the windshield fogs up, you can't see. Given our climate and terrain, the windshield inside can fog up instantly and without warning. If the defrost isn't working, we have to clear the windshield with a towel. This generally is a multi-stop event as it does not stay cleared very well without proper airflow. ALSO, the constant rebooting of the display unit is a serious distraction to the driver. The screen continuously cycles through multiple screens and the day night recognition function does not work. So if it is night time, the bright screen continuously reboots in front of your face. It is unacceptable in a 4 year old vehicle to have these issues and Nissan offer NOTHING and not acknowledge the fact that their vehicles have a serious safety issue. This part is a problem and no amount of "normal wear and tear" explains its failure. It is simply a faulty component from the manufacturer. My wife regularly has our 3 children in the car with her. It is not a good situation. Even if Nissan offered to pay for the part and I the labor I would be happy. To acknowledge nothing is unacceptable