If it were my car I would first check the front wheel bearing adjustment. Try grabbing the top of the tire (car stopped of course) and rock. If the wheel bearings are really loose you'll feel it as a slight clunck ... clunk. Check both sides.
Although obvious, you could also test the wheel lug-nut tightness. Are you sure they are all snug and torqued properly?
Or if you are mechanically inclined, take off the wheel, pull off the dust cover in the hub center, get an allen that fits and adjust. This would also be a good time to make sure the wheel bearing has enough grease.
Have you had a FULL service recently?
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)