Just to chime in on the car mount discussion from a while back-- I picked up the universal mount they sell at the verizon store, which attaches either with an adhesive, or with a little spring mechanism to the vent (which is how I'm using it). It was $19.99
I'm usually really weary about buying any of the verizon brand stuff but I'm really liking this. It holds the phone very securely (I have my One in an otterbox commuter) but it's still easy to get in and out and seems like it would definitely fit whatever phone/case/etc. The vent isn't ideal since that vent obviously becomes less functional, but it feels very secure while also being a lot faster to get the whole unit on and off than a strong suction cup.
On the other hand the screen protectors I got there today were awful