During normal driving, the unit plus your own mirror begin to self adjust downward toward the floor, so I found myself constantly adjusting it back upwards. There may be a way on some auto mirrors to tighten the swivel device to make it more rigid.In terms of the operatino of the device, it was wonderful. The sound is clear, and it lights up with incoming messages, and is far less hassle than ear pieces and 12 other devices I have tried. I loved it except the mirror kept showing the tops of my shoes.