174,000 miles, new VR rated yokohama's and quality name-brand shocks all around. The car shakes above 55 mph. The tires were balanced along with a fresh 4-wheel alignment. New steering "shock" added a few months ago. The shake is all around the car, not just in the steering wheel. Could this be a driveline problem? Any suggestions? My other MB's with higher mileage (W123 + W107) never had this problem. I drive on 70 mph highways frequently and am embarrassed when grandma in a buick passes me!