Sixty4x4

Those vents do what many say on here and that is balance the vent system. It also prevents dust from blowing back in in a hotter windows down day. The early models have a vertical arranged rectangular piece whereas the later ones the rectangle is longer on the horizontal. They are not interchangeable and for some reason the older models are more expensive. But did make a difference. On the 2007-2010 you can change the vent without removing the tire carrier but you destroy the clips getting it out but who cares it is buggered anyway.