While driving on the highway yesterday I noticed a vibration and worsening noise. I exited the highway and pulled over into a parking lot. I observed the front air dam/lower valence had come undone. Upon further inspection I saw that 3 of the 9 10mm bolts securing the piece had apparently fallen out. I belong to a Toyota 4Runner forum (6thgen4runner.com) and searched for tis issue there and it is apparently occurring for a number of owners. As a precaution I had to remove the piece to prevent further damage to my vehicle or to others on the road.