Mostly stays secure in CD slot but depending on the automobile it blocks some controls for HVAC, radio, CD etc. I cannot use it in landscape mode with the power cable plugged into either of my smartphones (iPhone and Motorola). This may depend on the phone model.

They had another Mountek device that hooks on the vents of the car's HVAC system.  This model gets one (1) star. First off the phone easily slides out of the holder and lands on your console or the floor or your car. It just does not hold the phone tightly. Worse it does not clamp well to the vents and the whole setup (phone and holder) comes falling down especially it you hit a bump. This happened to me twice so I tossed the unit in the trash. Note: this unit also has the power cable problem noted above when in the landscape position.
Mostly stays secure in CD slot but depending on the automobile it blocks some controls for HVAC, radio, CD etc. I cannot use it in landscape mode with the power cable plugged into either of my smartphones (iPhone and Motorola). This may depend on the phone model. They had another Mountek device that hooks on the vents of the car's HVAC system. This model gets one (1) star. First off the phone easily slides out of the holder and lands on your console or the floor or your car. It just does not hold the phone tightly. Worse it does not clamp well to the vents and the whole setup (phone and holder) comes falling down especially it you hit a bump. This happened to me twice so I tossed the unit in the trash. Note: this unit also has the power cable problem noted above when in the landscape position.