The whole car was vibrating. The steering wheel, seats, floor, the whole car. If the steering wheel shakes most of the time the problem is in the front and if the seats shake its in the rear. Maybe the guy balancing the tires messed up. I may take it back to check the balance.
Have them do a spin balance on the car. That will then balance everything that rotates. If the problem is still there, then start checking for loose ball joints and other suspension parts. find out if the wheels were put on with a impact wrench only, or if they used a torque wrench at 100 foot pounds.