My Focus has 20,000 klm on it now and I have been plagued with vibration problems coming through the steering also the cabin.
I thought I had the problem solved when one tire company said that one of the Conti contact tires was out of round. I had that replaced and the car was better but I could still fill this slight vibration through the car.
I finally took the car to another tire company and they took the tires off the rim and then refitted them and rebalanced them. The car at last is smooth and only a slight vibration, the guy that balanced the tires said that all my tires had high and low spots on them every where.
At least I know what the problem is now and soon as the tires wear out a bit I will be eagerly replacing them with tires that are not out of round and better quality