Strange interior rattle

I searched but nothing seems to match the noise I am hearing. I realize these trucks are not a luxury vehicle and are prone to rattles and noises but if anyone has some advice on this that would be great.

Around 40-43mph and going over any slight bumps in the road I hear a rattling noise from the driver side doors. I can't pin point it to which one. It also doesn't happen every time I drive, example, I drove to the gym and back home this morning with no noise but on my way to work I heard it. I've tried pressing on as many surfaces as I can to see if it helps, but no luck yet. Today, I also noticed that if i crack the windows I don't hear it but if i push on the glass when closed the noise still happens.

 

I have that from the passenger side door. I've never taken the door off to investigate. It's like a buzz as the engine rpm hits a certain level and makes whatever is touching in there vibrate. If I push on the door near the kick panel it stops. Seriously after 2 years I don't even hear it anymore.

 

I recently changed out my factory mirrors for heated ones and when I took the panel off, I found this in the door. No signs of a break in so I'm thinking this was left in at the factory by accident. While I never heard it rattle, it's something to consider.

 

I'm planning on installing new speakers and deadening the door. So I will have to investigate when I do.

It's strange that it just started happening this past weekend. I was wondering if there was something common that loosens up over time and causes this.

 

I've owned four Tacomas and they've all had a dash or door rattle/buzz. The buzz on my S-Runner was so bad I took it to the dealer. While they had it they backed it into a pole and screwed up the bumper. They gave me a Scion xA for a week while they repainted my bumper. I should have just dealt with the buzz.

 

What kind of noise is it really? This is what mine sounds like..

https://youtu.be/zdpDNR_hx10

 

Not the same as mine. Another strange discovery, the days that I was hearing the rattle I was low on gas like less than 1/4 tank. Filled up and haven't heard it since that day...