Yes, to enable parking monitoring mode, you need a hardwire kit. This kit is not included and please purchase separately. SKU: GW41.0100. 

Hello, please check if the rear camera is fully inserted into the dash cam main body. 

So when it powers off, it goes into a sleep mode. That sleep mode doesn't require alot of power, but if you have it set to turn on if the camera detects vibrations, it uses the cars battery. Mine is plugged in all the time and it only powers on when I turn the car on or it feels vibrations. With the vibration setting, it will turn on when I open my car door. But if your power source isn't powered when the car shuts off, then it doesn't use any power, just what the camera has stored up. Hope that helps 

Yes …. You can use anywhere it goes with you… I use mine in our camper 

With this filter, I can reduce my shutter speed, even with a sunny day, so in my photos I get a blur motion background. Same thing with video, you can reduce the shutter speed so you will get more motion blur. It you consider for portrait, this filter don’t add blur background. For that you need a 2.8 or faster lens. I hope this help