I've tried vent holders and cd mount holders and this was by far the best option for us.
It may just be our cupholders, but it doesn't stay as well as I'd like. It still works well for us so we will be keeping it.
Tryone Auto Backseat Tablet Mount Holder For IPad Air Mini, Cell Phone, Galaxy Tab, Kindle Fire HD Switch Lite Or Other 4.7-10.5" Devices - Black
18 Review
PERLESMITH Tilt TV Wall Mount Bracket for 32-70 inch LED, LCD, OLED and Plasma Flat Screen TVs - Fits 16β- 24β Wood Studs, Tilting TV Mount with Max VESA 600 x 400mm hold up to 132lbs - Enhanced SEO
12 Review
BMK Adjustable Stand For Amazon Echo Spot - 360 Degree Horizontal & 40 Degree Vertical Rotation, With Ball Bearings Bracket For Speaker Mounting, Ideal For Home And Office Use (Black)
21 Review
Tryone Car Headrest Tablet Mount Holder: Stretchable Stand For IPad Air Mini/Cell Phone/Galaxy Tab/Kindle Fire HD/Switch Lite 4.7-10.5" Devices
13 Review