I use the Mobius. It is used in the RC model community because it is so compact and light.
I have mine mounted under my rear view mirror pointed forward. Nice thing about the Mobius is lots of support and help on the internet.
As a dash camera you can program it to come on automatically and to loop. You hook up the USB mini jack and feed it power from the switched 12vdc and it will turn on with the ignition. Also you can program it to flip the image so you mount it upside down.
Software is easy to use. It has an LED on the back so you know it is recording as a dash camera.
And a kit costs from $50.00 to $85 on eBay and Amazon. Lots of accessories too.
A VERY good dash cam with lots of features for little money.....and it is so tiny it is easy to conceal for theft and cop reasons.
Produces quick time files.
Here is the full scoop on these cameras.
The Mobius ActionCam Support Thread (Posts #1-#8 mandatory reading!) - RC Groups
http://www.amazon.com/Mobius-Action-Camera-1080P-Sports/dp/B00DP1WYD2/ref=sr_1_1?ie=UTF8&qid=1395422500&sr=8-1&keywords=mobius+camera
16GB Mobius Actioncam Full HD Sports Camera 1080p 30fps 720P 60FPS Camcorder | eBay