The contact owns a 2016 GMC Sierra 1500. The contact stated that her husband remote started the vehicle. The contact stated that when the vehicle was started, the defrosters automatically activated. The vehicle warmed up for approximately 2 to 3 minutes. The contact stated that while leaving the driveway, her husband stopped the vehicle to assist with moving a lawn mower. Upon returning to the vehicle and looking through the glass her husband observed that there was smoke coming from the rear glass. The contact stated that her husband unlocked the rear doors and released the folding rear seat and saw that the defroster unit was on fire and smoking. The contact stated that her husband turned the vehicle off and the flames were self-extinguished; however, approximately 45-seconds later the driverâs side rear panel window shattered. The vehicle was not taken to a local dealer or independent mechanic to be diagnosed or repaired. The contact researched online and related the failure to Customer Satisfaction Program Number: N192265660 - Rear Window Defroster Thermal Events (Electrical System, Visibility). The manufacturer was informed of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 89,000.