Anyone know what this is for? It's behind the grate-like plastic when the tailgate is up.


Grate at tailgate

Rubber flaps behind grate

On the inside of the car, it is covered by a white insulation/padding. Thanks in advance!

 

Almost all vehicles have that. It is a vent to release air/cabin pressure from the cabin to the outside. Some vehicles have it in the rear quarter panel and covered by the bumper mold. Think about all the air that gets sucked in from the front to the inside of the cabin, it needs to be released somewhere or the cabin will become a high pressure zone.

 

Thanks, that helps. I was wondering if it would be a problem if one of the flaps was left open permanently. Sounds like not an issue.

 

It may cause dust to enter if it is left open. By design these exhaust vents are meant to open if the cabin has positive pressure.
On the D5 they are high enough that I don’t think water entering would be an issue.

 

That makes sense about the dust. I could live with that I think. I did measure the height. The top parts of the venting is above the wading depth (which was where I was looking to run the wire), but the bottom parts are not. I would find it hard to believe that they would keep water out. It's very flimsy rubber.

 

Haven’t looked closely at the D5, but on my older Toyota the flap shuts when the outside pressure is higher. Not a super strong seal, but will prevent water rushing in, but not from seeping in. Not a big deal until you have to back up in deep water or going out of a riverbed.