Check out UBMT (Ubiquitous Multimedia Technology) View-T Wide camera system for cars. It has a front and rear camera that can record in HD (1280 x 720) quality, with a 3.5-inch screen for split real time view.
Shaped like a camera, my first thought is that it is a camera. On closer look, you will realize some differences. For example, the back is a full 3.5-inch screen. No special buttons and not designed for you to hold.
On the top is a latch that looks like a cold shoe for camera flash. It is actually catered for mounting this camera on the windscreen.
Here is the mounting.
And the lens is super big for a car camera system. The lens has a 140 degree angle.
Here is the MicroSD card slot.
Power on/off switch
And here are some accessories that you can connect to the camera.
Additional Battery Module
I forgot to take the picture of the rear camera. Here is one picture from their website.
Here are some specs for your reference. One important feature that I need to mention here is that it has buffer memory in it. That means there will be no gap in the segments while recording.