LexPegged

I was doing some maintenance on my car today and noticed that for some reason, the round rubber seal under the spare tire was removed. There was basically a hole in the floor. Fortunately I was able to locate the seal and simply put it back on to close the opening.
I decided to continue looking around and removed the styrofoam with the tools on the left hand side in the trunk under the carpet (see pic) and noticed that the area under there was full of little pebble stones. I was wondering how the heck did the stones make their way in there and saw something that kind of shocked me. Right above the area (where you might have a jack, for some reason mine has been placed on the right hand side of the trunk) there is a vent. Yes, there is a strange vent that is open to the outside to, I'm guessing let the air in or out of the trunk. It has a light rubber trap so it only allows to open one way. There are actually two of those vents, one on top of the other. What exactly is it used for, because in my opinion not only does it let sound in, but possibly even exhaust fumes, but also small stones as was the case with my car.
Anyone know if this is normal feature of any car, just newer vehicles, or exclusive to Lexus and what purpose does it really serve?

Blue Moose Engineering

My 95 Civic had those so that's something cars have had for a long time...yes it's probably a safety air vent.