I just purchased 4 new tires Cooper Lifeliner SLE (225 50 17) and have attempted to balance them 3 times at 3 different places. Also recently resurfaced the front rotors and installed new ceramic pads. Unfortunately there still a noticeable vibration between 60 and 65 mph. Any ideas? I heard the Continental ContiExtreme are very popular as OEM replacements for this vehicle. Would it be worth trying the Continental?