I recommend taking a look at the G1W, there are a few variants G1W-C (capacitor), G1WH (wider lens).
For the relatively cheap price of ~$40 it shoots really good day & night videos.
My day time capture, sorry for the radio-music: http://www.youtube.com/watch?v=7v_2eRbZR-Q
It takes about 2-3 weeks to ship. I would also be careful, purchase it from a reputable seller there are a few places that are selling knockoffs at a similar price.
I have two, and they're mounted to both our vehicles. I ran the wire similar to this video
through the side panels and glove compartment, and fished the excess into the overhead. I'm using the cigarette lighter port. There are videos online where people are using some advanced setups, tapping directly into the car's electrics (front reading light). You can definitely play around with that.
When I looked for a dashcam, I was mostly interested in whether it can cope with our cold winters and hot summers. After 2 years of using them, I've yet to have any issues, and one of the cars is kept outside all year long. Finding a dashcam with a wider lens is also better, because it captures a lot more of the road.https://dashcamtalk.com
is the authority when it comes to dashcams, take a look through there.