One problem related to steering wheel vibrate has been reported for the 2008 Mercury Mariner Hybrid. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Mercury Mariner Hybrid based on all problems reported for the 2008 Mariner Hybrid.
The power torque sensor for the power steering was already recalled and had the system updated before I got the car in 2014. The cars steering wheel starts shaking a little then all of a suddle the steering wheel locks up and the power steering stops working, so you can't hardly turn it. I came inches from getting in a wreck. You can update the system but it will only work for about 1 or 2 years.