Modern cars all will "drum" badly with only one window open. Even my 85 Volvo is bad, have to crack the opposite rear window to keep the wind from drumming into my years. The W124 blows directly into my ear from behind with the windows open!
Crack a window, the noise goes away. It's the price we pay for such clean aerodymamics.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!