As dom says, get the one he linked to.
For the money, it's a good little setup. Covering front and rear of the car in one neat, compact unit.
It'll do the job you want for very little outlay.
Mine's almost a year old & only problems I had was from using a class 10 SD card. Now using a class 6 and no problems.
I'm hankering after the mobius because it's the latest from the manufacturers of the 808 keyfob cams. I used to own the
#16 - a very good little cam but not really a dashcam (no auto start/stop), it's primary task was a simple spy-type device. The remote control community took it to heart for its size/quality. The mobius is supposed to be the pinnacle.
It's as good as similarly spec'd/priced cams (such as the DR32) but half the size & a presenting aspect barely larger than its lens.
For me, the best point (aside from video quality & pedigree) is the smartphone app & the ability to set the camera up from the phone, view footage & download if needed.
This could be a really useful feature at the scene of an accident - being able to get a file & send by email or bluetooth to police?