Excellent if your device is in a case or skin (or without).  These mounts are what you need so that your back seat passengers can watch movies or play games.  Great for keeping the kids occupied during those long trips.

Don't confuse this mount with those that use velcro straps.  These clamp securely onto the metal posts that support your headrest.  The tablet sits within a an expandable cradle.  Installation and removal can be done in a matter of seconds.  

These mounts support your tablet in landscape mode as shown.

Fits many models including:

Acer Iconia A100

aPad

Amazon Kindle Fire

Apple iPad and iPad2

Acer Iconia A500

AOC Breeze

Archos: 101, 70, 7c

Asus EEE Pad: MeMo, Transformer, Transformer Prime

BlackBerry PlayBook

Cambridge Sciences G7-II

Coby Kyros: MID7005, MID 7015, MID7025, MID7026

Dell Streak 7

Eken M009s

eLocity A7

Google Nexus 10

HeroTab

HP: Slate, TouchPad

HTC: Flyer, Jetstream

LG G-Slate

Motorola: Xoom, Xoom 2, XYboard 8.2, XYboard 10.1

NATPC M009s

Samsung Galaxy Tab, Samsung Galaxy Tab 2 7.0, Galaxy Tab 8.9

Sony Tablet S

SuperPad

Tabtech: A816, M010s

Tabtronics: M009s, WM8650

Toshiba Thrive

Velocity Cruz T301

ViewSonic: gTablet, ViewPad 10, ViewPad 7

Vizio 8

Take a look at these pictures.  We're going outside to watch a movie.  You can too after buying this mount!