Though its an old post, but i think I can add some value for future members if they have similar issue. Vibration is usually caused by one of following things, so checking each is step by step solution.
-- Check the wheel balancing and make sure it shows ZERO on both sides of tire.
-- Check the wheel alignment including the toe-in, toe-out and camber alignment.
-- Check the wheel bearing
-- Check the harmonic balancer that is placed usually around the center axle to balance the car weight equally on both sides.