Just to add to MBDoc.. yes the wood is that easy. Pry up that little plastic surrounding of the shifter... and then pull at the wood from the front... it should pull right up.
As for your vents, I get that too sometimes when it's on high speed. It doesn't sound like a smooth stream of air (from the center vents)... it just sounds like there are many obstacle the air must go around. When I have the center vent partially shut, I too hear that whining noise... but there's not a lot of the whining noise otherwise, but still some.
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!)