I've had the Thinkware F770 front dashcam hardwired to my car for 3 years, and 6 months before that in my previous car with no problems (other than the irritating speed camera warnings, although you can turn that feature off);
https://www.thinkware.com/Products/Dashcam/F770
I fitted it behind and just to the left of my rear view mirror so it's not visible from the driving seat.