What is this vent/things purpose?

Yeah or you could be a jerk on the forum, that's cool too and still gives OP his answer. Hope you don't ever come across anything you didn't know about your truck. By the way, questions like this are a pretty big part of the purpose of the forum. Way to promote them.

 

Its so you dont blow the windows out when you fart.

 

X2
A know-it-all is easy to spot around here.

... Then he has the balls to call us 'retarded'.

 

Always noticed in my 06 when I closed any one of the doors while the windows were up that door wouldn't slam hard... and the roof would even actually flex upward.

If I closed one of them with a window cracked down, that door would slam surprisingly hard.

I guess that's one reason for that vent, among others. Glad my 06 didn't come with it though... the soundproofing is bad enough already.

 

All cars and trucks cabins have a vent somewhere. Your 06 does too.