Dashcam Research Survey

I am just trying to understand, what is meant by a wireless rear cam that still plugs in for power. Would it connect wirelessly to front cam for some reason? Maybe to use the little LCD screen on the front cam? Why not just have it display on the phone screen instead so that it can be a totally separate device not dependent on the front cam?

I definitely like the wide angle suggestion.

I haven’t yet gotten any rear facing dash cam. Is there a benefit to having one actually in the back of the vehicle not recording the cabin as opposed to recording the cabin and the back windshield like several do? I’m guessing it is more clear in the back?