What's this on the back of my cab

About a week ago I started getting a flapping/rattle sound when driving my 2008 Tacoma 4x4 Access Cab. I finally found the culprit...between the cab and the bed there is a small oval recessed area on the backside of the cab and a piece of rubber was hanging most of the way out. It has several small holes punched across the top that fasten it and had somehow worked it's way loose. I could barely pull it the rest of the way out because there's not much room.....my question is what is the recess for in the back of the cab and do I need this piece of rubber in there. Any help would be appreciated.

 

there is a vent on the back wall of the cab to allow for the changes is pressure inside the cab.

 

What ever you do...DO NOT seal it up. If you are ever involved in an accident where the airbags deploy. You are going to want them babies to work as designed. If that pressure has no where to go, you might of survived the crash but you head just caved in from that pressure of the airbags going off.

 

^Someone do that and take video. I would pay to see that.

 

nah.....more like ND!!!

 

Yeah, you're too helpful, Chris. We need to talk a noobie into this.

 

That's the best idea you've had in a long time!!!!!

 

Thanks for the advice.....do I need to get this rubber flap put back in or forget about it.

 

I wanna watch!!