I've also heard of problems with wireless cameras. I ended up with
https://www.amazon.com/gp/product/B078YNW5R5/. The main unit with front facing camera straps onto the existing rear view mirror and then it has a wired rear camera that goes to the back. It records both the front and rear views like a dashcam if desired.
Pros:
Supposed to have lane departure warning but I haven't tried it.
As a mirror it's nice and big and shows a wider view than my factory one.
The camera images are nice and bright, much more so than an old dash cam I had.
Supposed to lower the rear view when you put the vehicle in reverse but I haven't tried that feature yet.
The front camera has a silver ring around it that could possibly draw attention to it. Possible theft deterrent?
It comes with a GPS receiver so you can see your speed and a moving map of the location when reviewing video with their included software.
Very easy mounting, the front unit just straps to your mirror. I was able to just stick the rear camera to a magnet stuck to the inside of a rear window. It's held so far!
Cons:
Pricey.
The cameras have quite wide angles so "objects are closer than they appear".
The front camera has a silver ring around it that could possibly draw attention to it. Possible theft attractant?
The rear camera does not use a standard video connection so substituting a different camera could pose a challenge.
It can be a little discombobulating because the mirrored view is there along with the rear camera view at the same time. You have to adjust where your eyes are focusing to switch between the two views and sometimes it throws you off. (Although you can shut off the camera view so it's just a mirror if desired; recording is unaffected)
I've had the unit several months now and yes, I would buy it again.