I don’t have one in my car but have a cheap one on my wife’s car that I got from Amazon for like $35. It’s some generic Chinese brand. It’s just ok, nothing to rave about. Picture is good if in front of our car, once it goes to the sides it’s not so easy to read plates, even though it’s 1080p. Sound is pretty mediocre and just having the stereo kinda loud in the car causes a ton of distortion in the audio portion of the recording, can hardly understand what a passenger says in the car. I told my wife I’d hard wire hers to the mirror and have yet to do it, it’s been a year lol. So there’s a wire connecting the camera to the 12V port.
Overall I don’t think I’d recommend going cheap, if you want a reliable recording you might want to spend more money. I hear Blackvue is great and they do have models that recording front and back.