This one works for me. Sticks on the dash amazingly, easily adjustable.

iOttie Easy View 2 Car Mount Holder https://www.amazon.com/dp/B00JUXPHWE/ref=cm_sw_r_other_awd_9DMQwbG8FYBB0

I have this case on my phone for reference

Nexus 6 Case, Spigen [Air Cushioned Bumper) https://www.amazon.com/dp/B00OH4I7UU/ref=cm_sw_r_other_awd_AONQwbN2Z5FAV

I got this one, works with my case on. This thing will NOT come off your dash. The suction cup on this thing is awesome. http://www.amazon.com/gp/product/B00JUXPHWE