We had to unclog our daughter's sunroof drain and it worked. Hubby watched the YouTube video and worked at it slowly so not to puncture and drain tubes. It was stopped up with leaves that has decayed and worked their way down the drain tube.
I can't tell you all he did but he did have to work from the roof then crawl under the car and work from there! You'll need an air compressor and some thin wire and lots of water in a cup, don't use the hose! That's about all I can remember seeing him use! 4951