Grrrr, if I have to take that damn panel off again... well i guess I have to, so I won't complain about it. So the duct that leads up to the drivers side dash runs down through there? How big is it and what does it look like? I will check that out, seems like the only possibility. Everything else opens and closes fine, including the front foot vents, I can see them open and close.
Only thing I am curious about is this: When I have AC on, it comes out front dash vents to matter what. If I put the setting on windshield and feet, then it still comes out of the vent, although quite lightly, but if I push the dash vent button, it comes out full blast. It only does this on AC, so I am pretty sure it's normal.
2006 E350 w/ 155k miles (Daily Driver)
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)