After the car had been sitting in the sun, I tried to open the sun roof in a parking lot, smoke started coming from the headliner. The windows would not work at that point and I had to exit the car after turning the ignition off. Later, I had found that a zip tie was used to bundle the wires and connect them to a metal bar. It had frayed the wires causing a short. The smoke had engulfed the cabin, because I could not open the windows at that time and any time afterwards. If I had been driving on a highway I could have crashed. I have heard that underdash heater motor shorts have done the same thing.