What the hell is that thing?

[As a Weapon]

I am going to pick up a rear bumper for my car tomorrow at the junk yard. Its already painted and the guy I talked to said it's in flawless condition so I decided its worth $235 (kinda more than I wanted to spend). Anyway, I'm pretty busy this week (because I'm going on vacation next week) so I decided to use the free time I had tonight to take my wrecked bumper off. When I got the bumper off I found this goofy little flap door thing on the driver's side rear. I have absolutely no idea of what it is or what its functions are. Does anybody know what the heck that thing is for?

[JOHN_B]

Its the vent. Open and close your door, to see it works.

[As a Weapon]

Yeah I realize its some sort of vent and when I close my hatch it pops open...but why? Its probably just to help the hatch close better or something. I think I'm gonna build one of those things where if someone is chasing you you just press a button and tacks fall out the back of your car and pop the person's tires ha ha...just kidding. Oh wait, no I'm not.

[Gas-n-Grease]

the vent is to help move air inside the cabin, like say, you have all your windows up and blowing ice cold a/c. there's a maximum amount of air volume in the cabin that the car can hold. by blowing cold air from the a/c, you're adding more air the a confined space. if that vent wasn't there, the interior would build up a lot of air pressure (although the cabin isn't air tight). The vent is to relieve the extra air.... and doubles as a tack fall out.

[Swing Fixer]

.... and doubles as a tack fall out.

:chuckles:

[nccelica]

Strange story about that vent... I purchased my car awhile back and went to put my rear bumper from my kit on. I saw the vent and something was sticking out of it, I was like, "What the hell is that?" After much trouble, I got it out. It was the tighten knob that goes on top of the spare tire to keep it from moving. Now how it got in my air cabin vent.... that's beyond me.