I got a Viofo A119M V3 as an "Amazon Renewed" deal for $69, and got one that seems in like-new condition.
I also purchased the Viofo hardwire kit, which you route to the fuse box, find some appropriate fuses to tap, pull the fuses, install the probably-won't-start-fires fuse taps, route the wires to the dashcam, don't interfere with the airbags...
It's a lot easier for me to reach the fuse box after removing the glove box. Be sure to carefully remove the two different wire assemblies before pulling too hard.
But you don't have to do any of that.
Rear view mirrors these days have electronics in them to auto dim during UFO encounters. So there's a power connector.
Dongar Technologies makes a little box that coverts the power for the mirror into voltage that works with the dash camera.
I didn't want 24-hour constant camera vigilance. I wanted a not-dead 12V battery in the morning. The rear view mirror power is great for that: always energized when the car is on (regardless of Park Drive Reverse), and remains so for about 10 minutes after the car is powered off.
Despite Dongar's website, which claims there's no support for the i3, I found an adapter that just works. Plugging it in was super easy.
DCA-LRS
Kit with two styles of writing harness.
I had to buy a mini (NOT micro!) USB cable to do USB-C from the power adapter to the USB mini B on the Viofo camera.
Kit with two styles of writing harness.
https://dongar.tech/products/dongar-classic?variant=47763275022560
I'm not sure if the photos make sense. Every electronic device is black plastic, this helps you not see anything at all. It's like that in real life during installation, as well.
I used the iFixit spring steel pry tool to shuck the rear view mirror housing. It's tough plastic.
My 2020 doesn't have the Tech Package camera, so I put the dashcam there.
The rain sensor is looking up, through the windshield, I believe. There is a forward-looking CdS light sensor that senses daylight and adjusts the iDrive display, and maybe where I put the power cable and camera will interfere with that.
So far it seems fine.
No visible wires.