I had a vibration forever at between 55-65 mph. Balance and balance and balance again with results for short time. For the first time since I have owned my car, I had an amazing low speed drive through town with no vibration.

I currently battle a high speed vibration during braking and I have new brakes and rotors all around, new fluid, and all, and I thought they were related. (similar feel of head shake).

Car is tight now, fun to drive, and the braking has improved also. Perhaps cheap rotors were not the best investment but I was sure that new was better than old.

Bought some cheap LBJ's from ebay. $18 each. Some of the best money I have spent so far on my X fire

 

Same here. Had a vibration at the same speed. got new tires and was cured for a while but returned. mercedes shop said right control arms needed repacement .Replaced bushings and ball joints on both sides along with a tie rod. $1200 dollars later the vibration is worse. The tech said the wheels were out of round because I drove on the new tires too long. He said it might correct itself but I dont see how. One new tire coming this week. Hopefully this will cure the problem once and for all . The car as of now is unenjoyable to drive.