Hitting noise coming from back seat area, when start the car. 23 prius

Before I go to dealer, I wanted to write here.

When you start the car, I hear this noise. First, it's like a buzzing sound, not from the brake actuator. But like some motor is engaging. (around 1 second)

Right after I hear "tık tık tık tık tık" sound, then it stops. It's like it's trying to do something but it can't.

That sound coming from back seat area.
When I turn on the car and run back to trunk and listen, I don't hear much. So it's not coming from trunk. It's somewhere in the back seat.

Usually it's coming when car sits longer time before I start.

Maybe from fuel pump? Or some doors for fan in the back seat? Not sure. Do you hear something like this?

I will go to dealer but I am sure they won't diagnose and won't care because it doesn't come every time and needs effort to hear.

 

I will try. Its low sound but I will try to record. I know its difficult to understand if you dont have the same noise. But that also means its not normal and something is wrong with my car

 

This is the video. first video, I played with the sound so it is louder. Second one as is.

 

Edit: I am getting closer to find where that sound coming from. When I open the gas cap, then close it, sit in the car and close the door, that sound comes.

That means something is engaging after closing the gas cap. Chatgpt says it might be evap pressure sensor or something like that.

 

Update: That noise coming from here:

sound comes everytime I open the gas cap and close it, and close the doors.

 

I am not sure. When my gas is low, I might take the hoses out and take it. There might be something inside stuck. I will take a closer look. Also, I can not find the exact part on google anywhere. Neither Toyota parts or rockauto. Part no on repair manual is 77070A but when I google it, the result is sligly different part. I dont have check engine code also.

 

nice shot. I wont pay that, dealer has to pay that. I went there few months ago for service campain (About fuel stuff), but they did wrong thing that day and they had to keep the car one more day. After that this sound started to come. But I dont have any proof. I will go there and see what they say