Here's a quick look at the official HTC One Car Dock. It's a car dock, for the HTC One. And if you're at all familiar with HTC's car docks for its other devices, you should be right at home here.
There's nothing grossly different about the functionality here. It's got a substantial base that either suctions itself to your windshield, or to your dash via an adhesive disc. (I usually opt for the windshield, but then again I swap devices more than most normal folks.) You twist the textured ring at the base of the dock to trigger the suction mechanism. (It's easier to do when you're actually mounting the dock, so don't worry if you can't just get it to work in your hands.) There's a ball joint to allow for a full range of movement and positioning of your phone, and there's just enough friction to keep things from moving when you don't want them to.