While lowering the convertible top on my Mini Cooper Convertible, the trunk partition was not fully in place. Normally, the vehicle will prevent the roof from operating or provide a notification if the partition is not correctly positioned. In this case, the safety interlock system failed to warn me or stop the roof from lowering. While the roof was folding, the rear glass shattered, causing $6,000 in damage. The dealership confirmed that the rear parcel shelf was not fully in place and explained that the sensor only detects one side(in my case the trunk partition was in its place on one side ) , allowing the top to operate even when unsafe. They did not cover the damage under warranty. The vehicle was inspected by the authorized Mini Cooper dealership at the time of the incident. No police or independent inspections have been conducted. No warning lamps, messages, or alerts appeared, and the roof operated normally, giving no indication that the partition was not fully in place. The vehicle was only three months old. The shattered glass spread throughout the backseat and trunk area, creating a serious risk of injury to any passengers in the rear. Luckily no one was in the back at the time of the incident