While driving slowly between 5mph to 10 mph on our bumpy rocky country road, there was a loud knocking noise emanating from the front left fender area. Craig Fletcher at Atkinson Toyota-Bryan, Texas drove my car and his 2008 Prius on the same bumpy road for comparison. He said our noise was ten times as loud as his Prius. With 40K miles, he determined that the steering column torque sensor torsion rods were hitting stops inside the column, and replaced the steering column under the Toyota Platinum warranty. Our 2006 Prius had 50K miles and did not have this sound, driving on the same country road.
