This is Bull Sh*t! you buy a new a car or truck and you get this, leaves in the lower vents, I brought it back to ford two times, and they don't know what's going on, I have done research on this, and what i found is that the blend door (could) be broken, but I'm not sure, ford checked and they said there was nothing wrong the blend door, the only way to check this is to pull the dash apart, So again, ( why am I getting leaf debris in the vent system) if anybody has this problem please let me know, and the fix to it, Thanks for reading.