This is a step by step guide of how to do it:
1) Open the window of the drivers door.
2) Open and close the door of the side of the co-driver few times, creating draft that will blow all the hot air outside.
The creators of this video claim that this process will reduce the temperature inside the vehicle for 10 degrees in Celsius, or 50 degrees in Fahrenheit.
Now, this advice does come from Japan, so you probably won’t understand a single word from what they are saying, but, since it is a video after all, you won’t be needing words – all you need to do is watch.