2004 BMW X3 power windows

I have a 2004 BMW X3 which I bought new in 04. In 2005, someone was riding in the back seat and started to put the window down and there was a loud pop (as loud as a gun shot). I didn't know what was wrong until I could hear air coming in the window. I called Hendrick Motors where I bought the car and took it in. They diagnosed as needs replacement window regulator, and they replaced it. The exact same thing just happened again and I called my dealership and they told me it could be several things and I told then that I would not pay to have this window fixed. This is the 2nd. time it has happened...sounds like a defect in this model. What should I be prepared to do if it is the same problem? Thank you.