Oh, no, it’s not a secret! But what do you mean what happened? Does something happen to the audio? Or are you asking how I got the rain sounds in there? Let me know! Thanks for watching!
Based on what you can see in the video, I think it might have started hailing rather than just raining. Looks like pea-sized hail bouncing into frame. So maybe he was trying to move his car to protect it from damage?