Yada BT50424F-1 Tiny Traveler Baby Monitor for the Car, brand new in box.  The pics are from my daughters camera and they don't show the quality of the picture in person. 
The color pic is in daylight, the other is night vision.  Super easy to install, just plug into the lighter, then run the wire on the floor to the back.  No wiring needed.
This model currently on amazon for $100.
Specs:
3.5" Color Monitor mounts on dash.            
Camera can be mounted to the headrest or by suction cup (included) to ensure you have the best view.            
Use for front or rear facing baby seats - or to monitor anything that sits behind you.            
Night Vision allows you to see your baby even in the dark.