My car is almost 4 years old less 5 months. The Sunroof was installed bu third party contractor from the dealer. While I was driving two weeks ago and not using the sunroof, the window of the sunroof blew off my car. My insurance claims this might be due to a faulty install or product. Who is liable and should make repairs?

Third party contractor.

If this installation was done 4 years ago when you purchased the car, I doubt if any liability remains.

I agree with ScottGem, if the mod was not recently done.