I have front and rear cameras hardwired. I bought two Viofo A119 Mini 2's, because running a wire from the front to the back was too much of a chore in this exact car.
I used the Dongar hard wire adapters, generic for the rear, and 10 pin Type E for the front
I hardwired a Redtiger dashcam in my 2022 CX-9 earlier this year. I also hardwired a Redtiger dashcam in my wife's 2006 Civic. I used the video below for guidance as I had never hardwired a dashcam before, and it helped a ton.
I also found this video, which goes into a little more detail and may be just as helpful.
For a grounding connection, I used the bolt that secures the in-cabin fusebox to the car. For running cables, I did the same thing I did for my previous dashcam (Viofo A129 Duo), shown in the video below: