I'm pretty sure that as long as the camera isn't hidden, you're good to go. I remember the case a few years ago about the motorcycle rider who got in trouble for eavesdropping for using a dash cam and the courts ended up ruling in his favor.

 

as long as you have the cig lighter adapter plugged into a switched 12v source(which 2011+ dont have so i tapped another outlet into the fuse box) it goes on and off with the car. starts recording within 3secs of startup. As well its got a battery so you just hit the power button to manually turn it on or use it as a normal camera. (kinda hard to hardwire it in as the cig adapter has a 12v to 5v power converter built into it)

The 1080 is nice but is bit heavy in file size at about 105mb per min so i run it usually in 720 mode. which is just over half that size.

 

I believe the eavesdropping law does not apply if there is no audio. Saw something about it on a news show.