Mirror overlay dash cam versus windshield mounted?
 

I am checking out the following, the advantage to KDLINKS HD mirror is it doesn't block your field of view. The wheel witness advantage may be a bigger better camera lens. Your thoughts are appreciated....

https://www.amazon.com/KDLINKS-R100-Anti-Glare-Rearview-Superior/dp/B01L17EMP4

https://www.amazon.com/WheelWitness-Dash-Cam-PRO-PLUS/dp/B01NH7J3D7/ref=sr_1_3?ie=UTF8&qid=1533145573&sr=8-3&keywords=wheel+witness[/SIZE]

I have had a windshield mounted dash cam for several years now. It sits some 4 inches above the dash and in the middle of my car (actually I have one in both cars). Has never been in the way or obstructive.

But a word to the wise, do not ever unplug it so you can plug in your phone to charge. I did that about a month ago and the next day a driver ran a red light and hit the front of my car. Yep, it was still unplugged and I was not able to prove that the lady actually ran a red light. Cost me $630 for a new bumper.

I've been able to position mine behind the rear view mirror in a way that it is almost entirely invisible to the drivers field of vision. I would see if you could do that first before buying a mirror integrated unit.